The magnetic viewer makes the mysterious tracks recorded onto the tape visible
We have recently acquired a magnetic viewer in order to aid our digitisation work. By pressing the viewer against the tape we are able to read the magnetic information recorded on it. The reader helps us to visually identify the position of the recorded tracks on the tape, and enables accurate playback during digitisation. Magnetic readers can also help us to identify potential problems with the tape, for example if a track has been partially erased, because it will show up on the viewer.
We receive tapes that are in varying states of repair and disrepair. Sometimes the person who made the recording kept the tapes in impeccable, temperature controlled conditions. Inscribed on the boxes are dates and lists of who performed, and what instrument they played. The tapes often feature detailed notes about the number of tracks recorded, whether they are in stereo or mono and if they used noise reduction technology. Digitisation, in such cases, does not usually pose great challenges.
At the other extreme are tapes recorded by people who never wrote anything down about how they made their recording. This means the people doing the digitising can be left to do a lot of guess work (particularly if that person has since died, and can’t tell you anything about the recording). A lack of informative metadata about the tape does not necessarily create migration difficulties: recordings can be very straightforward like, for example, a ½ track stereo recording of a single voice.
It is essential that the appropriate head is used to read the magnetic information recorded onto the tape.
Problems can however arise when recordings have been made in an idiosyncratic (and inconsistent) manner. For example (and in exceptional circumstances) we receive single magnetic tapes that have a mixture of track formats on them which include four track multi-track, ½ and ¼ track mono and ½ and ¼ track stereo.
In such cases it can be hard to discern the precise nature of the recordings using the ears alone. Often such recordings don’t sound ‘quite right’, even if it is not exactly clear what the problem is.
Rather than relying on speculation, using the magnetic reader gives 100% confirmation about where tracks are recorded on the tape, and therefore helps us to replay the tape using the appropriate playback heads, and therefore digitise it accurately.
The summer of 2008 saw a spate of articles in the media focusing on a new threat to magnetic tapes.
The reason: the warm, wet weather was reported as a watershed moment in magnetic tape degradation, with climate change responsible for the march of mould consuming archival memories, from personal to institutional collections.
The connection between climate change and tape mould is not one made frequently by commentators, even in the digital preservation world, so what are the links? It is certainly true that increased heat and moisture are prime conditions for the germination of the mould spores that populate the air we breathe. These spores, the British Library tell us
‘can stay dormant for long periods of time, but when the conditions are right they will germinate. The necessary conditions for germination are generally:
• temperatures of 10-35ºC with optima of 20ºC and above
• relative humidities greater than 70%’
The biggest threat to the integrity of magnetic tape is fluctuations in environmental temperatures. This means that tape collections that are not stored in controlled settings, such as a loft, cupboard, shed or basement, are probably most at risk.
While climate change has not always been taking as seriously as it should be by governments and media commentators, the release today of the UN’s report, which stated in no uncertain terms that climate change is ‘severe, pervasive and irreversible’, should be a wake up call to all the disbelievers.
To explore the links between climate change and tape degradation further we asked Peter Specs from US-based disaster recovery specialists the Specs Brothers if he had noticed any increase in the number of mouldy tapes they had received for restoration. In his very generous reply he told us:
‘The volume of mouldy tapes treated seems about the same as before from areas that have not experienced disasters but has significantly increased from disaster areas. The reason for the increase in mould infected tapes from disaster areas seems to be three-fold. First, many areas have recently been experiencing severe weather that is not usual for the area and are not prepared to deal with the consequences. Second, a number of recent disasters have affected large areas and this delays remedial action. Third, after a number of disasters, monies for recovery seem to have been significantly delayed. We do a large amount of disaster recovery work and, when we get the tapes in for processing fairly quickly, are generally able to restore tapes from floods before mould can develop. In recent times, however, we are getting more and more mouldy tapes in because individuals delayed having them treated before mould could develop. Some were unaware that lower levels of their buildings had suffered water damage. In other areas the damage was so severe that the necessities of life totally eclipsed any consideration of trying to recover “non-essential” items such as tape recordings. Finally, in many instances, money for recovery was unavailable and individuals/companies were unwilling to commit to recovery costs without knowing if or when the government or insurance money would arrive.’
Nigel Bewley, soon to be retired senior sound engineer at the British Library, also told us there had been no significant increase in the number of mouldy tapes they had received for treatment. Yet reading between the lines here, and thinking about what Pete Specs told us, in an age of austerity and increased natural disasters, restoring tape collections may slip down the priority list of what needs to be saved for many people and institutions.
Mould: Prevention Trumps the Cure
Climate change aside, what can be done to prevent your tape collections from becoming mouldy? Keeping the tapes stored in a temperature controlled environment is very important – ’15 + 3° C and 40% maximum relative humidity (RH) are safe practical storage conditions,’ recommend the National Technology Alliance. It is also crucial that storage environments retain a stable temperature, because significant changes in the storage climate risk heating or cooling the tape pack, making the tension in the tape pack increase or decrease which is not good for the tape.
If you are wondering how mould attacks magnetic tape, it is attracted to the binder or adhesive that attaches the layers of the tape together. If you can see the mould on the tape edges it usually means the mould has infected the whole tape.
Optical media can also be affected by mould. Miriam B. Kahn writes in Disaster Response and Planning for Libraries
‘Optical discs are susceptible to water, mould and mildew. If the polycarbonate surface is damaged or not sealed appropriately, moisture can become trapped and begin to corrode the metal encoding surface. If moisture or mould is invasive enough, it will make the disc unreadable’ (85).
Prevention, it seems, is better than having to find the cure. So turn on the lights, keep the air flowing and make the RH level stable.
We are pleased to announce that we are now able to support the transfer of 2″ Quadruplex Video Tape (PAL, SECAM & NTSC) to digital formats.
2” Quad was a popular broadcast analogue video tape format whose halcyon period ran from the late 1950s to the 1970s. The first quad video tape recorder made by AMPEX in 1956 cost a modest $45,000 (that’s $386,993.38 in today’s money).
2” Quad revolutionized TV broadcasting which previously had been reliant on film-based formats, known in the industry as ‘kinescope‘ recordings. Kinescope film required significant amounts of skilled labour as well as time to develop, and within the USA, which has six different time zones, it was difficult to transport the film in a timely fashion to ensure broadcasts were aired on schedule.
To counter these problems, broadcasters sought to develop magnetic recording methods, that had proved so successful for audio, for use in the television industry.
The first experiments directly adapted the longitudinal recording method used to record analogue audio. This however was not successful because video recordings require more bandwidth than audio. Recording a video signal with stationary tape heads (as they are in the longitudinal method), meant that the tape had to be recorded at a very high speed in order accommodate sufficient bandwidth to reproduce a good quality video image. A lot of tape was used!
Ampex, who at the time owned the trademark marketing name for ‘videotape’, then developed a method where the tape heads moved quickly across the tape, rather than the other way round. On the 2” quad machine, four magnetic record/reproduce heads are mounted on a headwheel spinning transversely (width-wise) across the tape, striking the tape at a 90° angle. The recording method was not without problems because, the Toshiba Science Museum write, it ’combined the signal segments from these four heads into a single video image’ which meant that ‘some colour distortion arose from the characteristics of the individual heads, and joints were visible between signal segments.’
The limitations of Quadruplex recording influenced the development of the helical scan method, that was invented in Japan by Dr. Kenichi Sawazaki of the Mazda Research Laboratory, Toshiba, in 1954. Helical scanning records each segment of the signal as a diagonal stripe across the tape. ‘By forming a single diagonal, long track on two-inch-wide tape, it was possible to record a video signal on one tape using one head, with no joints’, resulting in a smoother signal. Helical scanning was later widely adopted as a recording method in broadcast and domestic markets due to its simplicity, flexibility, reliability and economical use of tape.
This brief history charting the development of 2″ Quad recording technologies reveals that efficiency and cost-effectiveness, alongside media quality, were key factors driving the innovation of video tape recording in the 1950s.
Often the tapes we receive to digitise are ‘forgotten’ recordings. Buried under a pile of stuff in a dark, cold room, their owners think they are lost forever. Then, one day, a reel of the mysterious tape emerges from the shadows generating feelings of excitement and anticipation. What is stored on tape? Is the material in a playable condition? What will happen to the tape once it is in a digital format?
All of these things happened recently when Paul Travis sent us a ¼ inch AMPEX tape of the band he played in with his brother, the Salford Oi! punk outfit State Victims. The impetus for forming State Victims emerged when the two brothers ‘split from Salford bands, Terrorist Guitars and the Bouncing Czechs respectively, and were looking for a new musical vessel to express and reassert their DIY music ethic, but in a more vital and relevant way, searching for a new form of “working-class protest.”‘
The tape had been in the wilderness for the past 30 years, residing quietly in a shed in rural Cambridgeshire. It was in fairly good condition, displaying no signs of damage such as mould on the tape or spool. Like many of the AMPEX tapes we receive it did need some baking treatment because it was suffering from binder hydrolysis (a.k.a. Sticky Shed Syndrome). The baking, conducted at 49 Celsius for 8 hours in our customised oven, was successful and the transfer was completed without any problems. We created a high resolution stereo 24 bit/ 96 kHz WAV file which is recommended for archived audio, as well as a MP3 access copy that can be easily shared online.
Image of tape post-transfer. When it arrived the tape was not wound on neatly and there was no leder tape on it.
Finding old tapes and sending them to be digitised can be a process of discovery. Originally Paul thought the tape was of a 1983 session recorded at the Out of the Blue Studios in Ancoats, Manchester, but it became apparent that the tape was of an earlier recording. Soon after we digitised the first recording we received a message from Paul saying another State Victims tape had ‘popped up in an attic’, so it is amazing what you find when you start digging around!
Like many other bands connected to the Manchester area, the digital artefacts of State Victims are stored on the Manchester District Music Archive (MDMA), a user-led online archive established in 2003 in order to celebrate Greater Manchester music and its history. The MDMA is part of a wider trend of do it yourself archival activity that exploded in the 21st century due to the availability of cheap digital technologies. In what is arguably a unique archival moment, digital technologies have enabled marginal, subcultural and non/ anti-commercial music to widely circulate alongside the more conventional, commercial artefacts of popular music. This is reflected in the MDMA where the artefacts of famous Manchester bands such as The Smiths, The Fall, Oasis and Joy Division sit alongside the significantly less famous archives of the Manchester Musicians Collective, The Paranoids, Something Shady and many others.
Within the community-curated space of the MDMA all of the artefacts acquire a similar value, derived from their ability to illuminate the social history of the area told through its music. Much lip service has been paid to the potential of Web 2.0 technologies and social media to enable new forms of collaboration and ‘user-participation’, but involving people in the construction of web-based content is not always an automatic process. If you build it, people do not always come. As a user-led resource, however, the MDMA seems pretty effective. It is inviting to use, well organised and a wide range of people are clearly contributing, which is reflected in the vibrancy of its content. It is exciting that such an online depository exists, providing a new home for the errant tape, freshly digitised, that is part of Manchester’s music history.
2014 will no doubt present a year of new challenges for those involved in digital preservation. A key issue remains the sustainability of digitisation practices within a world yet to establish firm standards and guidelines. Creating lasting procedures capable of working across varied and international institutions would bring some much needed stability to a profession often characterized by permanent change and innovation.
In 1969 The EIAJ-1 video tape was developed by the Electronic Industries Association of Japan. It was the first standardized format for industrial/non-broadcast video tape recording. Once implemented it enabled video tapes to be played on machines made by different manufacturers and it helped to make video use cheaper and more widespread, particularly within a domestic context.
The introduction of standards in the digitisation world would of course have very little impact on the widespread use of digital technologies which are, in the west, largely ubiquitous. It would however make the business of digital preservation economically more efficient, simply because organisations would not be constantly adapting to change. For example, think of the costs involved in keeping up with rapid waves of technological transformation: updating equipment, migrating data and ensuring file integrity and operability are maintained are a few costly and time consuming examples of what this would entail.
Although increasingly sophisticated digital forensic technology can help to manage some of these processes, highly trained (real life!) people will still be needed to oversee any large-scale preservation project. Within such a context resource allocation will always have to account for these processes of adaptation. It has to be asked then: could this money, time and energy be practically harnessed in other, more efficient ways? The costs of non-standardisation becomes ever more pressing when we consider the amount of the digital data preserved by large institutions such as the British Library, whose digital collection is estimated to amass up to 5 petabytes (5000 terabytes) by 2020. This is not a simple case of updating your iphone to the next model, but an extremely complex and risky venture where the stakes are high. Do we really want to jeopardise rich forms cultural heritage in the name of technological progress?
The US-based National Digital Stewardship Alliance (NDSA) National Agenda for Digital Stewardship 2014 echoes such a sentiment. They argue that ‘the need for integration, interoperability, portability, and related standards and protocols stands out as a theme across all of these areas of infrastructure development’ (3). The executive summary also stresses the negative impact rapid technological change can create, and the need to ‘coordinate to develop comprehensive coverage on critical standards bodies, and promote systematic community monitoring of technology changes relevant to digital preservation.’ (2)
File Format Action Plans
One step on the way to more secure standards is the establishment of File Format Action Plans, a practice which is being increasingly recommended by US institutions. The idea behind developing a file format action plan is to create a directory of file types that are in regular use by people in their day to day lives and by institutions. Getting it all down on paper can help us track what may be described as the implicit user-standards of digital culture. This is the basic idea behind Parsimonious Preservation, discussed on the blog last year: that through observing trends in file use we may come to the conclusion that the best preservation policy is to leave data well alone since in practice files don’t seem to change that much, rather than risk the integrity of information via constant intervention.
What are the other main challenges facing ‘digital stewards’ in 2014? In a world of exponential information growth, making decisions about what we keep and what we don’t becomes ever more pressing. When whole collections cannot be preserved digital curators are increasingly called upon to select material deemed representative and relevant. How is it possible to know now what material needs to be preserve for posterity? What values inform our decision making?
To take an example from our work at Great Bear: we often receive tapes from artists who have achieved little or no commercial success in their life times, but whose work is often of great quality and can tell us volumes about a particular community or musical style. How does such work stand up against commercially successful recordings? Which one is more valuable? The music that millions of people bought and enjoyed or the music that no one has ever heard?
Ultimately these questions will come to occupy a central concern for digital stewards of audio data, particularly with the explosion of born-digital music cultures which have enabled communities of informal and often non-commercial music makers to proliferate. How is it possible to know in advance what material will be valuable for people 20, 50 or 100 years from now? These are very difficult, if not impossible questions for large institutions to grapple with, and take responsibility for. Which is why, as members of a digital information management society, it is necessary to empower ourselves with relevant information so we can make considered decisions about our own personal archives.
A final point to stress is that among the ‘areas of concern’ for digital preservation cited by the NDSA, moving image and recorded sound figure highly, alongside other born-digital content such as electronic records, web and social media. Magnetic tape collections remain high risk and it is highly recommended that you migrate this content to a digital format as soon as possible. While digitisation certainly creates many problems as detailed above, magnetic tape is also threatened by physical deterioration and its own obsolescence challenges, in particular finding working machines to play back tape on. The simple truth is, if you want to access material in your tape collections it needs now to be stored in a resilient digital format. We can help, and offer other advice relating to digital information management, so don’t hesitate to get in touch.
What a year it has been in the life of Great Bear Analogue and Digital Media. As always the material customers have sent us to digitise has been fascinating and diverse, both in terms of the recordings themselves and the technical challenges presented in the transfer process. At the end of a busy year we want to take this opportunity to thank our customers for sending us their valuable tape collections, which over the course of 2013 has amounted to a whopping 900 hours of digitised material.
We feel very honoured to play a part in preserving personal and institutional archives that are often incredibly rare, unique and, more often than not, very entertaining. It is a fairly regular occurrence in the Great Bear Studio to have radio jingles from the 60s, oral histories of war veterans, recordings of family get-togethers and video documentation of avant-garde 1970s art experiments simultaneously migrating in a vibrant melee of digitisation.
We have also received a large amount of rare or ‘lost’ audio recordings through which we have encountered unique moments in popular music history. These include live recordings from the Couriers Folk Club in Leicester, demo tapes from artists who achieved niche success like 80s John Peel favourites BOB, and large archives of prolific but unknown songwriters such as the late Jack Hollingshead, who was briefly signed to the Beatles’ Apple label in the 1960s. We always have a steady stream of tapes from Bristol Archive Records, who continue to acquire rare recordings from bands active in the UK’s reggae and post-punk scenes. We have also migrated VHS footage of local band Meet Your Feet from the early 1990s.
On our blog we have delved into the wonderful world of digital preservation and information management, discussing issues such as ‘parsimonious preservation‘ which is advocated by the National Archives, as well as processes such as migration, normalisation and emulation. Our research suggests that there is still no ‘one-size-fits-all’ strategy in place for digital information management, and we will continue to monitor the debates and emerging practices in this field in the coming year. Migrating analogue and digital tapes to digital files remains strongly recommended for access and preservation reasons, with some experts bookmarking 15 April 2023 as the date when obsolescence for many formats will come into full effect.
While the world is facing a growing electronic waste crisis, Great Bear is doing its bit to buck the trend by recycling old domestic and professional tape machines. In 2013 we have acquired over 20 ‘new’ old analogue and digital video machines. This has included early 70s video cassette domestic machines such as the N1502, up to the most recent obsolete formats such as Digital Betacam. We are always looking for old machines, both working and not working, so do get in touch if your spring clean involves ridding yourself of obsolete tape machines!
Our collection of test equipment is also growing as we acquire more wave form monitors, rare time-based correctors and vectorscopes. In audio preservation we’ve invested heavily in early digital audio machines such as multi-track DTRS and ADAT machines which are rapidly becoming obsolete.
We are very much looking forward to new challenges in 2014 as we help more people migrate their tape-based collections to digital formats. We are particularly keen to develop our work with larger archives and memory institutions, and can offer consultation on technical issues that arise from planning and delivering a large-scale digitisation project, so please do get in touch if you want to benefit from our knowledge and experience.
Once again a big thank you from us at Greatbear, and we hope to hear from you in the new year.
We were recently sent a very interesting collection of recordings of the late poet, novelist and acclaimed translator Paul Roche. During his colourful and creative life Roche published two novels, O Pale Gallellean and Vessel of Dishonour, and several poetry collections, and brushed shoulders with some of the 20th century’s most captivating avant-garde artistic and literary figures. His faculty colleague when he worked at Smith College, MA in the late 1950s was none other than Sylvia Plath, who pithily described Roche’s ‘professional dewy blue-eyed look and his commercially gilded and curled blond hair on his erect, dainty bored aristocratic head’.
His intense 30 year friendship with painter Duncan Grant was immortalised in the book With Duncan Grant in Southern Turkey, which documented a holiday the friends took together shortly before Grant’s death. The relationship with Grant has often eclipsed Roche’s own achievements, and he is often mistakenly identified as a member of the Bloomsbury group. Roche also achieved success beyond the literary and scholarly world when his translation of Oedipus the King became the screenplay for the 1968 film starring Christopher Plummer and Orson Welles.
The recordings we were sent were made between 1960-1967 when Roche worked at universities in America. Roche experienced greater professional success in America, and his translations of Ancient Greek are still used in US schools and universities. His son Martin, who sent us the tapes, is planning to use the digitised recordings on a commemorative website that will introduce contemporary audiences to his father’s creative legacy.
The Great Bear Studio has been pleasantly awash today with the sound of Roche reading poetry and his dramatic renditions of Sophocles’ ‘Oedipus the King’, ‘Oedipus at Colonus’ and ‘Antigone’. The readings communicate his emphatic pleasure performing language via the spoken word, and an unique talent to immerse listeners in images, rhythm and phrases.
Listen to Paul Roche reading his translation of ‘Antigone’.
Our own pleasure listening to the recordings has however been disrupted because of frequent snaps in the tape. The tapes are covered in splices, which suggests they had been edited previously. Over time the adhesive glue has dried out, breaking the tape as it moves through the transport. The collection of tapes as a whole are fairly brittle because the base film, which forms the structural integrity of the tape, is made of acetate.
Canadian-based digitisation expert Richard Hess explains that
‘Acetate was the first widely used base film, with Scotch 111 being in production from 1948 through 1972/73, a total of 24-25 years. Acetate tape is generally robust and has the advantage of breaking cleanly rather than stretching substantially prior to breaking when overstressed. Acetate tapes residing in collections are over 30-years-old, with the oldest being over 60-years-old.’
The big downside to acetate is that when it degrades it loses its flexibility and becomes a bit like an extended tape measure. This means it is harder to pass the tape consistently through the tape transport. This is colloquially known in the digitisation world as ‘country-laning’, when the tape changes shape in all dimensions and becomes wiggly, like a country lane. To extend the metaphor, a well functioning tape should be flat, like, one supposes, a motorway.
When a tape is ‘country-laning’ it means tracks of recorded material are moving slightly so they shift in and out of phase, dis-aligning the angle between the tape head(s) and tape, or azimuth. This has a detrimental effect on the quality of the playback because the machine reading the recorded material on the tape is at odds with surface area from which the information is being read.
If you are reading this and wondering if the base film in your tape is made of acetate, or is made of another substance such as paper or polyester, you can perform a simple test. If you hold the tape against the light and it appears translucent then the tape is acetate. There may also be a slightly odd, vinegar smell coming from the tape. If so, this is bad news for you because the tape is probably suffering from ‘Vinegar Syndrome’. Richard Hess explains that
‘Vinegar syndrome occurs as acetate decomposes and forms acetic acid. This is a well-known degradation mode for acetate film. High temperature and humidity levels, the presence of iron oxide, and the lack of ventilation all accelerate the process. Once it has started it can only be slowed down, not reversed.’
Acetate tape is also particularly vulnerable to excessive heat exposure, which makes it shrink in size. This is why you should never bake acetate tape! When acetate tape is exposed to heat it reaches what is known as the liquid-glass transition phase, the temperature where the material composition starts to change shape from a hard and relatively brittle state into a molten or rubber-like state. Although glass transition is reversible, it certainly is destructive. In other words, you can change the tape back from molten to a hard substance again but the tape would be unplayable.
While acetate backed tape has certain advantages over polyester tape in the migration process, namely it is easier to cleanly splice together tape that has broken as it has moved through the transport, unfortunately acetate tape is more fragile, and can get extremely stiff which makes it difficult to play back the tape at all. Even if you can pass the tape through the machine it may snap regularly, and will therefore require a lot of treatment in the transfer process. So if you have a valuable tape collection stored predominantly on acetate tape, we strongly recommend getting it migrated to digital format as soon as possible due to the fragility of the format. And if that whiff of vinegar is present, you need to move even more quickly!
An important part of digitisation work we do is tape restoration. Often customers send us tape that have been stored in less than ideal conditions that are either too hot, cold or damp, which can lead to degradation.
In the excellent Council on Library and Information Sources’ report on Magnetic Storage and Handling (1995), they set the ideal archival storage conditions for magnetic tape at ‘significantly lower than room ambient (as low as 5 centrigade)’, with no less than 4 degrees variation in temperature at 20% room humidity. They suggest that ‘the conditions are specifically designed to reduce the rate of media deterioration through a lowering of the temperature and humidity content of the media.’
Of course most people do not have access to such temperature controlled environments, or are necessarily thinking about the future when they store their tape at home. Sometimes manufacturers recommended to store tape in a ‘cool, dark place’, but often tape is not adorned with any such advice. This leads to us receiving a lot of damaged tape!
As we are keen to emphasise to customers, it is possible to salvage most recordings made on magnetic analogue tape that appear to be seriously damaged, it just requires a lot more time and attention.
For example, we were recently sent a collection of 3” multi-track tapes that had been stored in fairly bad conditions. Nearly all the tapes were degraded and needed to be treated. A significant number of these tapes were AMPEX so were suffering from binder hydrolysis, a.k.a. sticky shed syndrome in the digitisation world. This is a chemical process where binder polymers used in magnetic tape constructions become fragmented because the tape has absorbed water from its immediate environment. When this happens tapes become sticky and sheds when it is played back.
Baking the AMPEX tapes is a temporary treatment for binder hydrolysis, and after baking they need to be migrated to digital format as soon as possible (no more than two weeks is recommended). Baking is by no means a universal treatment for all tapes – sticky shed occurs due to the specific chemicals AMPEX used in their magnetic tape.
Cleaning shedding tape
Other problems occur that require different kinds of treatment. For example, some of the 3” collection weren’t suffering from sticky shed syndrome but were still shedding. We were forewarned by notes on the box:
The tapes recorded on TDK were particularly bad, largely because of poor storage conditions. There was so much loose binder on these tapes that they needed cleaning 5 or 6 times before we could get a good playback.
We use an adapted Studer A 80 solely for cleaning purposes. Tape is carefully wound and rewound and interlining curtain fabric is used to clean each section of the tape. The photo below demonstrates the extent of the tape shedding, both by the dirty marks on fabric, and the amount we have used to clean the collection.
You might think rigorous cleaning risks severely damaging the quality of the tape, but it is surprising how clear all the tapes have sounded on playback. The simple truth is, the only way to deal with dry shedding is to apply such treatment because it simply won’t be able to playback clearly through the machine if it is dirty.
Loss of lubricant
Another problem we have dealt with has been the loss of lubricant in the tape binder. Tape binder is made up of a number of chemicals that include lubricant reservoirs, polymers and magnetic particles.
Lubricants are normally added to the binder to reduce the friction of the magnetic topcoat layer of the tape. Over time, the level of the lubricant decreases because it is worn down every time the tape is played, potentially leading to tape seizures in the transport device due to high friction.
In such circumstances it is necessary to carefully re-lubricate the tape to ensure that it can run smoothly past the tape heads and play back. Lubrication must be done sparingly because the tape needs to be moist enough to function effectively, but not too wet so it exacerbates clogging in the tape head mechanism.
Restoration work can be very time consuming. Even though each 3″ tape plays for around 20 minutes, the preparation of tapes can take a lot longer.
Another thing to consider is these are multi-track recordings: eight tracks are being squeezed onto a 1/4″ tape. This means that it only takes a small amount of debris to come off, block the tape heads, dull the high frequencies and ultimately compromise the transfer quality.
It is important, therefore, to ensure tapes are baked, lubricated or cleaned, and heads are clear on the playback mechanism so the clarity of the recording can realised in the transfer process.
Now we’ve explored the technical life of the tape in detail, what about the content? If you are a regular visitor to this blog you will know we get a lot of really interesting tape to transfer that often has a great story behind it. We contacted Richard Blackborow, who sent the tapes, to tell us more. We were taken back to the world of late 80s indie-pop, John Peel Sessions, do it yourself record labels and a loving relationship with an 8 track recorder.
A Short History of BOBby Richard Blackborow
Back in 1983 I was a 17 year old aspiring drummer, still at school in North London and in an amateur band. Happily for me, at that time, my eldest brother, also a keen musician, bought a small cottage in a village called Banwell, which is 20 or so miles outside of Bristol, near Weston Super Mare. He moved there to be near his work. The cottage had a big attic room and he installed a modest 8-track studio into it so that he could record his own music during his spare time. The studio was based around a new Fostex A8 reel-to-reel machine and the little mixing desk that came with it.
The equipment fascinated me and I was a regular visitor to his place to learn how to use it and to start recording my own music when he wasn’t using it.
Skip forward a couple of years and I am now 19, out of school, deferring my place at university and in a new band with an old friend, Simon Armstrong. My brother’s work now takes him increasingly abroad, so the studio is just sitting there doing nothing. Simon and I begin to write songs with the express intention of going to Banwell every time we had a decent number of tunes to record. Over the next ten years it becomes part of the routine of our lives! We formed a band called BOB in 1986, and although we still lived in London, we spent a lot of time in that small studio in Banwell – writing, recording demos, having wild parties! By this time my brother had moved to the US, leaving me with open access to his little studio.
To cut a long story short, we loved that little studio and wrote and recorded some 300 songs over the ensuing 10 years…the studio gear finally dying in about 1995. Most recordings were for/by BOB, but I also recorded bands called The Siddeleys and Reserve (amongst others).
The tapes we recorded have been lying around for years, waiting to be saved!
Recent interest in BOB has resulted in plans to release two double CDs. The first contains a re-issued album, all the BBC sessions and a few rarities. The second CD, planned for next year, will contain all of the BOB singles, plus a whole CD of the best of those demos we recorded. It was for this reason that all of those old tapes were sent to Adrian to be transferred to digital. I now have a studio near my home in West Cornwall, close to Land’s End, where I will be mixing all the material that Great Bear have been working on. The demos map our progression from pretty rubbish schoolboy aspirants to reasonably accomplished songwriters. Some of the material is just embarrassing, but a good chunk is work I am still proud of. We were very prolific and the sheer number of reels that Adrian has transferred is testament to that. There is enough material there for a number of CDs, and only time will tell how much is finally released.
Listen to the recently transferred Convenience demo
This is a bit of a rarity! It’s the demo (recorded on the little 8-track machine in Banwell) for a BOB single that came out in 1989. It’s called Convenience and I wrote and sang it. This early version is on one of the tapes that Adrian has transferred, so, like many of the rest of the songs, it will be re-mixed this winter for digital formats and released next year.
If you want the latest news from BOB you can follow them on twitter. You can also pre-order the expanded edition of their 1991 album Leave the Straight Life Behind from Rough Trade. It will be available from the end of January 2014. A big thank you to Richard for sending us the photos, his writing and letting us include the recording too!
Digital technologies have helped to salvage all manner of ‘lost’ or ‘forgotten’ recordings. Whole record labels, from the recently featured Bristol Archive Records to institutional collections like Smithsonian Folkways, are based on the principle of making ‘hard to access’ recordings available in digital form.
Occasionally we get such rare recordings in the Great Bear studio, and we are happy to turn the signal from analogue to digital so the music can be heard by new audiences. Last week we were sent a particularly interesting collection of tapes: a box of nearly 40 3”-10.5” reel to reel tapes from the songwriter and artist Jack Hollingshead, who sadly passed away in March 2013. The tapes are in good condition, although the spools are pretty dirty, most probably from being stored under the bed or at the back of a cupboard, as these things often are! Jack’s tape came to our attention after a phone call from the writer Stefan Granados, who wanted to arrange for a few songs to be digitised for a research project he is doing focused around the Beatles’ Apple Records company.
The Beatles set up Apple Records in 1968 as an outlet for their own and emerging artists’ recordings. Well known performers who were signed to Apple included Mary Hopkin, Ravi Shankar, James Taylor and many others. But there were also a number of artists who recorded sessions with Apple, but for one reason or another, their music was never released on the label. This is what happened to Jack’s music. Jack’s Apple sessions are psychedelic pop-folk songs with striking melodies, song cousins of drowsy Beatles hits like ‘Across the Universe’. He recorded seven songs in total, which we received on magnetic tape and acetate disc, the test cut of the recording that would have been printed on vinyl. We digitised from the magnetic tape because the disc was in fairly poor condition and we didn’t know how many times the disc had been played.
Listen to ‘Vote for ME’ by Jack Hollingshead
It wasn’t the first time that Jack’s work had aroused record company interest. When he was 16 he signed a contract with Aberbach publishers. Like his experience with Apple a few years later, nothing came of the sessions, and because the companies owned the recordings, he was not able to release them independently.
Jack soon became very frustrated by the record industry in the late 1960s and decided he would do it himself. This was ten years before home recording became widely accessible, so it was not easy, either financially or technically.
In the 1970s a series of serious accidents, and a spell in prison, proved to be disruptive for his musical career. Jack’s prison sentence, received for growing marijuana he was using for medical pain relief purposes, was however fairly positive. It gave him time to focus on playing guitar and he wrote his best songs while incarcerated.
The back of a test acetate is grooveless
He continued to write and record music throughout his life, and there is a significant amount of material that Trina Grygiel, who is responsible for managing Jack’s estate, is determined to organise and release in his memory.
Jack was also prodigiously talented artist in other mediums, and turned his hand to puppet making, wax painting, gardening and property restoration. His obituary described him as a ‘perfectionist, in all his artistic, creative and practical endeavours he would settle for nothing less.’
We recently digitised some VHS tapes from when Bristol-based band Meet Your Feet performed on HTV in 1990. Meet Your Feet
‘formed in 1988 as a result of three of the women getting together to start a women’s music workshop, Meet Your Feet played its first gig in June 1988, when asked to get a set together for a Benefit Gig against section 28. This gig was so successful that the band decided to stay together and gradually the original line-up of the early years of the band evolved: Carol Thomas, vocals; Diana Milstein, founder member, bass and lyricist; Diggy, percussion; Heie Gelhaus, founder member, keyboards and songwriter; Julie Lockhart, vocals; Karen Keen, sax; Sue Hewitt, founder member, drums and songwriter; Vicki Burke, sax’ (taken from the Women’s Liberation Music Archive).
During the 80s the band achieved great success and performed at prestigious festivals such as Glastonbury and WOMAD, as well as appearing on Radio 4′s Women’s Hour. They played together until 1992 before disbanding, reformed in 2010 and continue to play shows in Bristol and beyond. Meet Your Feet’s style, which draws from Latin, Jazz and Soul influences, interspersed with passionate, upbeat political lyrics, align them with other ‘women’s music’ bands from the 1980s, such as The Guest Stars and Hi-Jinx.
The video clip we digitised is interesting because it indicates how novel women’s bands were in 1990.
After the band finish performing their new single, they take part in a short interview where they are asked:
‘Its an obvious question, but I am going to ask it, why all women?’
Julie Lockhart, one of the singers, responds wittily, but not without a tinge of bewilderment, ‘Um, we were born that way!’
Can you imagine an all male group being asked a similar question in a television interview, either now or in the early 1990s?! It just wouldn’t happen because no one notices if all the members of a group are male, it just seems completely normal.
The interview goes on to emphasise gender issues, rather than focus on other aspects, such as themes in their music or that it is a large group (there are nine people in the band after all, which is a lot!)
This is not a criticism of the interviewer’s questions as such. Yet the fact it was necessary to asks them about their gender speaks volumes about how surprising it was to see women playing music together. The interview continues as follows:
Presenter: Are there any real advantages to being an all female group?
Sue Hewitt: We listen to each other more, and spin ideas of each other a lot more easily
Julie Lockhart: We giggle a lot more
Presenter: Do you row a lot because you are on the road, its a hard life isn’t it, very intense?
Julie Lockhart: No, that’s the obvious difference we never row!
Presenter: Do you find it hard to be taken seriously by men who come to see an all girl band?
Sue Hewitt: Well no, not all the time. I think initially some men take the view of ‘oh well, its just a bunch of girls on stage’ but when we get up there and start playing they think, ohhh [they can play as well]
It is frustrating that such questions had to be asked, and maybe they wouldn’t be now – although it is still often the case that in music, as in other areas of cultural life, women’s gender is marked, while male gender is not. We have all heard, for example, the phrase ‘female-fronted band’. When do we ever hear of bands that are ‘male-fronted’?
It is really valuable to have access to recordings such as those of Meet Your Feet, not only as a documentation of their performances, but also to demonstrate the attitudes and assumptions that women faced when they participated in a male dominated cultural field.
It is also good to know that Meet Your Feet are still performing and undoubtedly upsetting a few stereotypes and expectations along the way, so make sure you catch them at a show soon!
‘The participatory art installation that I called “Clews” took place in “The White Room”, a bookable studio space at the Slade School of Art, over three days in 1979. People entering the space found that the room had been divided in half by a wooden wall that they could not see beyond, but they could enter the part nearest the entrance. In that half of the room there was a video monitor on a table with a camera above it pointing in the direction of anyone viewing the screen. There was also some seating so that they could comfortably view the monitor. Pinned to the wall next to the monitor was a notice including cryptic instructions that referred to part of a maze that could be seen on the screen. Participants could instruct the person with the video camera to change the view by giving simple verbal instructions, such as ‘up’, “down”, “left”, “right”, “stop”, etc. until they found a symbol that indicated an “exit”.’
My plan was to edit the video recordings of the event into a separate, dual screen piece but it was too technically challenging for me at the time. I kept the tapes though, with the intention of completing the piece when time and resources became available. This eventually happened in 2012 when, researching ways to get the tapes digitized, I discovered Greatbear in Bristol. They have done a great job of digitizing the material and this is the first version of piece I envisaged all those years ago.’
The oldest tape we have received at the Great Bear is a spool of paper backed magnetic tape, c.1948-1950. Its pretty rare to be sent paper backed tape, and we have been on a bit of adventure trying to find more about its history. On our trail we found a tale of war, economics, industry and invention as we chased the story of the ‘magnetic ribbon’.
The first thing to recount is how the development of magnetic tape in the 1930s and 1940s is enmeshed with events in the Second World War. The Germans were pioneers of magnetic tape, and in 1935 AEG demonstrated the Magnetophon, the first ever tape recorder. The Germans continued to develop magnetic tape, but as the 1930s wore on and war declared, the fruits of technological invention were not widely shared – establishing sophisticated telecommunication systems was essential for the ‘war effort’ on both sides.
Towards the end of the war when the Allies liberated the towns and cities of Europe, they liberated its magnetic tape recording equipment too. Don Rushin writes in ‘The Magic of Magnetic Tape.’
‘By late 1944, the World War II Allies were aware of the magnetic recorder developed by German engineers, a recorder that used an iron-powder-coated paper tape, which achieved much better sound quality that was possible with phonograph discs. A young Signal Corps technician, Jack Mullin, became part of a scavenging team assigned to follow the retreating German army and to pick up items of electronic interest. He found parts of recorders used in the field, two working tape recorders and a library of tapes in the studios of Radio Frankfurt in Bad Bauheim.’
In the United States in WW2, significant resources were used to develop magnetic tape. ‘With money no object and the necessity of adequate recording devices for the military, developments moved at a brisker pace’, writes Mark Mooney.
This where our paper tape comes into the equation, courtesy of Polish-born inventor Semi J. Begun. Begun began working for the Brush Development Company in 1938, who were one of the companies contracted to develop magnetic tape for the US Navy during the war. In his position at Brush Begun invented the ‘Sound Mirror.’ Developed in 1939-1940 but released on the market in 1946, it was the first magnetic tape recorder to be sold commercially in the US post WW2.
As the post-war rush to capitalise on an emerging consumer market gathered apace, companies such as 3M developed their own magnetic tapes. Paper backed magnetic tape was superseded toward the end of the 1940s by plastic tape, making a short but significant appearance in the history of recording media.
This however is a story of magnetic tape in the US, and our tape was recorded in England, so the mystery of the paper tape has not been solved. Around the rim of the rusted spool it states that it is ‘Licensed by the Brush Development Co U.S.A’, ‘Made in England’, ‘Patents Pending’ and ‘Therimonic Products Ltd.’
Therimonic were the British company who acquired the license to build the Soundmirror in 1948. Barry M Jones, who has collected a wider history of the British tape recorder, home studio and studio recording industries writes, ‘[Soundmirror] was the first British-built domestic tape-recorder, whereas the first British built-and-designed tape recorder was the Wright & Weaire, which appeared a few weeks later. Production began in autumn 1948 but the quality of the paper tape meant it shedded oxide too readily and clogged the heads!’
Production of the Soundmirrors continued to late 1954 so it is possible to date the tape as being recorded some time between 1948 and 1958. The weight of the spool and the tape is surprisingly heavy, the tape incredibly fragile, marking its passage through time with signs of corrosion and wear. It is a beautiful object, as many of the tapes we get are, that is entwined with the social histories of media, invention, economy and everyday life.
What is perhaps worse in the professional archive sector than changing the structure of the data, is not making a record of it in the metadata.
Metadata is a way to record all the journeys a data object has gone through in its lifetime. It can be used to highlight preservation concerns if, for example, a file has undergone several cycles of coding and decoding that potentially make it vulnerable to degradation.
‘technical data (info on resolution, image size, file format, version, size), structural metadata (describes how digital objects are put together such as a structure of files in different folders) and descriptive (info on title, subject, description and covering dates) with each type providing important information about the digital object.’
As the previous blog entry detailed, digital preservation is a dynamic, constantly changing sector. Furthermore, digital data requires far greater intervention to manage collections than physical objects and even analogue media. In such a context data objects undergo rapid changes as they adapt to the technical systems they are opened by and moved between. This would produce, one would speculate, a large stream of metadata.
What is most revealing about metadata surrounding digital objects, is they create a trail of information not only about the objects themselves. They also document our changing relationship to, and knowledge about, digital preservation. Metadata can help tell the story about how a digital object is transformed as different technical systems are adopted and then left behind. The marks of those changes are carried in the data object’s file structure, and the metadata that further elaborate those changes.
Like those who preserve physical heritage collections, a practice of minimal intervention is the ideal for maintaining both the integrity and authenticity of digital collections. But mistakes are made, and attempts to ‘clean up’ or otherwise clarify digital data do happen, so when they do, it is important to record those changes because they help guide how we look after archives in the long term.
In a blog post a few weeks ago we reflected on several practical and ethical questions emerging from our digitisation work. To explore these issues further we decided to take an in-depth look at the British Library’s Digital Preservation Strategy 2013-2016 that was launched in March 2013. The British Library is an interesting case study because they were an ‘early adopter’ of digital technology (2002), and are also committed to ensuring their digital archives are accessible in the long term.
Making sure the UK’s digital archives are available for subsequent generations seems like an obvious aim for an institution like the British Library. That’s what they should be doing, right? Yet it is clear from reading the strategy report that digital preservation is an unsettled and complex field, one that is certainly ‘not straightforward. It requires action and intervention throughout the lifecycle, far earlier and more frequently than does our physical collection (3).’
The British Library’s collection is huge and therefore requires coherent systems capable of managing its vast quantities of information.
‘In all, we estimate we already have over 280 terabytes of collection content – or over 11,500,000 million items – stored in our long term digital library system, with more awaiting ingest. The onset of non-print legal deposit legislation will significantly increase our annual digital acquisitions: 4.8 million websites, 120,000 e-journal articles and 12,000 e-books will be collected in the first year alone (FY 13/14). We expect that the total size of our collection will increase massively in future years to around 5 petabytes [that's 5000 terabytes] by 2020.’
All that data needs to be backed up as well. In some cases valuable digital collections are backed up in different locations/ servers seven times (amounting to 35 petabytes/ 3500 terabytes). So imagine it is 2020, and you walk into a large room crammed full of rack upon rack of hard drives bursting with digital information. The data files – which include everything from a BWAV audio file of a speech by Natalie Bennett, leader of the Green Party after her election victory in 2015, to 3-D data files of cunieform scripts from Mesopotamia, are constantly being monitored by algorithms designed to maintain the integrity of data objects. The algorithms measure bit rot and data decay and produce further volumes of metadata as each wave of file validation is initiated. The back up systems consume large amounts of energy and are costly, but in beholding them you stand in the same room as the memory of the world, automatically checked, corrected and repaired in monthly cycles.
Such a scenario is gestured toward in the British Library’s long term preservation strategy, but it is clear that it remains a work in progress, largely because the field of digital preservation is always changing. While the British Library has well-established procedures in place to manage their physical collections, they have not yet achieved this with their digital ones. Not surprisingly ‘technological obsolescence is often regarded as the greatest technical threat to preserving digital material: as technology changes, it becomes increasingly difficult to reliably access content created on and intended to be accessed on older computing platforms.’ An article fromThe Economist in 2012 reflected on this problem too: ‘The stakes are high. Mistakes 30 years ago mean that much of the early digital age is already a closed book (or no book at all) to historians.’
There are also shorter term digital preservation challenges, which encompass ‘everything from media integrity and bit rot to digital rights management and metadata.’ Bit rot is one of those terms capable of inducing widespread panic. It refers to how storage media, in particular optical media like CDs and DVDs, decay over time often because they have not been stored correctly. When bit rot occurs, a small electric charge of a ‘bit’ in memory disperses, possibly altering program code or stored data, making the media difficult to read and at worst, unreadable. Higher level software systems used by large institutional archives mitigate the risk of such underlying failures by implementing integrity checking and self-repairing algorithms (as imagined in the 2020 digital archive fantasy above). These technological processes help maintain ‘integrity and fixity checking, content stabilisation, format validation and file characterisation.’
300 years, are you sure?
Preservation differences between analogue and digital media
The British Library isolate three main areas where digital technologies differ from their analogue counterparts. Firstly there is the issue of ‘proactive lifestyle management‘. This refers to how preservation interventions for digital data need to happen earlier, and be reviewed more frequently, than analogue data. Secondly there is the issue of file ‘integrity and validation.’ This refers to how it is far easier to make changes to a digital file without noticing, while with a physical object it is usually clear if it has decayed or a bit has fallen off. This means there are greater risks to the authenticity and integrity of digital objects, and any changes need to be carefully managed and recorded properly in metadata.
Finally, and perhaps most worrying, is the ‘fragility of storage media‘. Here the British Library explain:
‘The media upon which digital materials are stored is often unstable and its reliability diminishes over time. This can be exacerbated by unsuitable storage conditions and handling. The resulting bit rot can prevent files from rendering correctly if at all; this can happen with no notice and within just a few years, sometimes less, of the media being produced’.
A holistic approach to digital preservation involves taking and assessing significant risks, as well as adapting to vast technological change. ‘The strategies we implement must be regularly re-assessed: technologies and technical infrastructures will continue to evolve, so preservation solutions may themselves become obsolete if not regularly re-validated in each new technological environment.’
Establishing best practice for digital preservation remains a bit of an experiment, and different strategies such as migration, emulation and normalisation are tested to find out what model best helps counter the real threats of inaccessibility and obsolescence we may face in 5-10 years from now. What is encouraging about the British Library’s strategic vision is they are committed to ensuring digital archives are accessible for years to come despite the very clear challenges they face.
In a 2012 report entitled ‘Preserving Sound and Moving Pictures’ for the Digital Preservation Coalition’s Technology Watch Report series, Richard Wright outlines the unique challenges involved in digitising audio and audiovisual material. ‘Preserving the quality of the digitized signal’ across a range of migration processes that can negotiate ‘cycles of lossy encoding, decoding and reformatting is one major digital preservation challenge for audiovisual files’ (1).
Wright highlights a key issue: understanding how data changes as it is played back, or moved from location to location, is important for thinking about digitisation as a long term project. When data is encoded, decoded or reformatted it alters shape, therefore potentially leading to a compromise in quality. This is a technical way of describing how elements of a data object are added to, taken away or otherwise transformed when they are played back across a range of systems and software that are different from the original data object.
To think about this in terms which will be familiar to people today, imagine converting an uncompressed WAV into an MP3 file. You then burn your MP3s onto a CD as a WAV file so it will play back on your friend’s CD player. The WAV file you started off with is not the same as the WAV file you end up with – its been squished and squashed, and in terms of data storage, is far smaller. While smaller file size may be a bonus, the loss of quality isn’t. But this is what happens when files are encoded, decoded and reformatted.
Subjecting data to multiple layers of encoding and decoding does not only apply to digital data. Take Betacam video for instance, a component analogue video format introduced by SONY in 1982. If your video was played back using composite output, the circuity within the Betacam video machine would have needed to encode . The difference may have looked subtle, and you may not have even noticed any change, but the structure of the signal would be altered in a ‘lossy’ way and can not be recovered to it’s original form. The encoding of a component signal, which is split into two or more channels, to a composite signal, which essentially squashes the channels together , is comparable to the lossy compression applied to digital formats such as mp3 audio, mpeg2 video, etc.
A central part of the work we do at Great Bear is to understand the changes that may have occurred to the signal over time, and try to minimise further losses in the digitisation process. We use a range of specialist equipment so we can carefully measure the quality of the analogue signal, including external time based correctors and wave form monitors. We also make educated decisions about which machine to play back tapes in line with what we expect the original recording was made on.
If we take for granted that any kind of data file, whether analogue or digital, will have been altered in its lifetime in some way, either through changes to the signal, file structure or because of poor storage, an important question arises from an archival point of view. What do we do with the quality of the data customers send us to digitise? If the signal of a video tape is fuzzy, should we try to stabilise the image? If there is hiss and other forms of noise on tape, should we reduce it? Should we apply the same conservation values to audio and film as we do to historic buildings, such as ruins, or great works of art? Should we practice minimal intervention, use appropriate materials and methods that aim to be reversible, while ensuring that full documentation of all work undertaken is made, creating a trail of endless metadata as we go along?
Do we need to preserve the ways magnetic tape, optical media and digital files degrade and deteriorate over time, or are the rules different for media objects that store information which is not necessarily exclusive to them (the same recording can be played back on a vinyl record, a cassette tape, a CD player, an 8 track cartridge or a MP3 file, for example)? Or should we ensure that we can hear and see clearly, and risk altering the original recording so we can watch a digitised VHS on a flat screen HD television, in line with our current expectations of media quality?
Richard Wright suggests it is the data, rather than operating facility, which is the important thing about the digital preservation of audio and audiovisual media.
‘These patterns (for film) and signals (for video and audio) are more like data than like artefacts. The preservation requirement is not to keep the original recording media, but to keep the data, the information, recovered from that media’ (3).
Yet it is not always easy to understand what parts of the data should be discarded, and which parts should kept. Audiovisual and audio data are a production of both form and content, and it is worth taking care over the practices we use to preserve our collections in case we overlook the significance of this point and lose something valuable – culturally, historically and technologically.