There’s a magic to objects that store audio material. Whether it’s the all-too-basic simplicity of grooves on a plasticky surface, the sci-fi feeling of laser-like colors on the underside of a CD, ones and zeroes hiding on a tiny hard drive or somewhere along the incomprehensibly vast network that is the internet, somehow we just push a few buttons and the air around us vibrates with sounds from a different time and place. Of all the audio formats, there is something particular about compact cassettes, though, and I’d like to share some of my thoughts about why this is.

The first part I’d like to share concerns the physical object that is the cassette, specifically something that all audio archivists know that many others do not: material recorded on cassettes (and other formats using magnetic tape) will be almost impossible to retrieve in the next 5-15 years. The second part is about the specific kinds of material that are recorded on cassettes, and what makes them especially unique and important to preserve.

Magnetic Tape: A Global Preservation Priority

For quite some time now humans have been captivated by new technologies. There’s a popular wisdom that the newer and more ‘high-tech’ something is, the better. From a preservation perspective though, this is a bit upside down. Clay tablets from places like Iraq and Palestine still survive after over three thousand years, while the material on your hard drive will keep for about twenty years – and that’s if it’s kept in ideal conditions! Depending on a whole host of factors, an optical drive disc, like a CD or DVD, can have a shelf life of between two and one hundred years, while a vinyl record could last for up to a thousand years – for the same reasons environmentalists tell us we need to reduce plastic consumption.

Magnetic tape formats, like cassettes, are one of the more vulnerable of the audio and video recording formats. The reasons for this may be unexpected if we limit ourselves to thinking that how long something will last depends only on how fast the material it is made from degrades. Don’t get me wrong, the material that some magnetic tape is made from does, indeed, degrade. To understand this, we need to get into the nitty-gritty of magnetic tape technologies.

What we think of as magnetic tape is made up of three layers. The most important layer, the one that stores the information, is called the oxide layer. It is coated with a metallic oxide (commonly iron oxide). When you press the record button on a tape recorder, the sound waves that hit the microphone are transformed into an electromagnetic pulse that the tape head uses to rearrange this metallic oxide to match the sound wave.

The oxide layer is very fragile, so it is glued onto a second layer, called the base layer. This is usually made of an acetate or polyester, so you can play or rewind the tape without it snapping. If we stopped here, once we roll the tape around itself, the electromagnetic field of the oxide layer on a particular part of the tape begins to affect the arrangement of metallic oxide on all the adjacent parts of the tape over time (this is called ‘print-through’). Various factors can affect how quickly this rearrangement of metallic oxide happens. One way around it is to alternate between rewinding the tape all the way for a period of storage, then forwarding it all the way for the next period. This ensures that the arrangement of electromagnetic fields across the tape are never in the same position for long enough to affect any other adjacent part. Some manufacturers worked to limit this by adding a third coating layer on the back of the strip of tape.

The most common types of magnetic tape degradation, other than print-through, are specific to the materials used by some manufacturers at particular times. The first of these is that the adhesive used by some manufacturers to glue the oxide layer to the base layer tends to absorb water molecules over time (scientists call this hygroscopy), which then seeps out of the tape and makes it unplayable (this is called ‘sticky-shed syndrome’). Preservation experts have a surprising way of dealing with this: they ‘bake’ the tape at particular temperatures to get the water out. The tape becomes more brittle, but you can at least transfer what’s on it to another carrier. The second major degradation factor affects magnetic tape with a base layer made of an acetate, which is the case with practically all magnetic tape carriers made before the 1960s when polyester became more widely used. Acetate breaks down over time, and causes the tape to shrink, become brittle and smell like vinegar. There is no real solution for this that can save the information recorded on the tape.

But as I hinted above, the issue with magnetic tape is not so much its degradation as another important factor: technological obsolescence. Nobody has mass-produced tape players for quite some time. This means that every time a tape player stops working, that’s one less tape player in the possession of humanity as a whole, and they’re effectively going extinct! (Side note: Wax cylinders have long faced this issue, and CD players are now in this category as well, while the recent return to an appreciation of vinyl records has meant that we’ve forestalled obsolescence for flat discs, though for the older shellac formats, there is an issue with non-standard shaped styli/needles that are fast disappearing). Another related issue is that of expertise; the last generation of engineers and specialists who know the ins and outs of magnetic tape playback machines and can help troubleshoot and fix them are now retiring. They have either trained up a new generation of specialists, or they have not, and their knowledge leaves with them.

In the well-resourced archives of the global north, institutions have been ringing these alarm bells since as early as the 1990s. In many such institutions, collections’ caretakers have launched major programs to digitize their at-risk collections. In some cases, these projects have been carried out at regional and even national levels. In the global south, however, such digitization projects are extremely rare when it comes to audio materials, and those that focus on magnetic tape are practically non-existent. Such projects require a great deal of resources, and though those resources may exist, it may be too late when the political will to direct such resources towards largescale digitization efforts materializes. In contexts of civil war, rampant corruption, poverty, unemployment, and global pandemics, diverting resources to the creation of digital archives can seem like a naïve and irresponsible luxury.

What’s on the tapes?

Magnetic tape as we know it was developed in Germany in the early 1930s, but it wasn’t widely used until radio broadcasting companies began to pick it up as a favored format in the late 1940s. This was not really something regular people could make use of; the tapes were on large reels and, even in their most portable versions, required pretty heavy equipment for recording and playback. In the early 1960s Lou Ottens, an engineer and inventor working for the Dutch company Philips managed to effectively shrink the whole apparatus of two tape reels into a plastic case: the compact cassette. By the mid-1970s, most people in the world with some disposable income could acquire a tape recorder and blank cassette tapes; regular people could now make their own recordings and could do this with equipment that was actually quite portable. By the end of that decade, Sony released the Walkman, and the equipment could now fit in a pocket! Until well after it was superseded by the compact disc (CD) around 2005, the compact cassette was the preeminent audio format. The period in between was the global cassette era.

Since you could now effectively fit a recording studio into a backpack, and without having to spend years of savings on it, the barriers to recording and distribution all but disappeared. You could record radio broadcasts, record yourself or others speaking or making music, or even secretly record a concert you were attending. If you had a tape recorder that had more than one deck, something quite common, you could record from one tape to others, mix and match from other recordings to make a mix-tape, or even make hundreds of copies of something at the quite inexpensive cost of buying enough blank tapes, the electricity/battery cost, and the time it took to do it. The surface of the tape itself and the packaging became an important canvas for all kinds of fonts, cover art, and photography. This also meant you could quite easily hide a recording by putting it on a cassette with misleading label, and maybe recording something else at the beginning and end of the cassette in case someone like a parent, a cop, or a border guard decided to actually try to listen to check on the tape’s contents.

The cassette era was a period of a democratization of audio recording. From the beginning of the audio recording era at the turn of the twentieth century until the cassette era, audio recording and distribution was something that only well-resourced bodies could carry out, resulting in large record labels and radio broadcasters dominating the world of recorded sound waves. The key determinants of what got recorded and heard were things like profit and political acceptability to those in power. Cassettes meant that sounds that were very local, subversive, experimental, unacceptable, and illegal could go from one time and place to another at a minimal cost.

Such ‘democratization’ is not all necessarily positive; how we evaluate the good or bad of technological development is, after all, completely a function of how it is used and the criteria we use to judge it. The cassette made it possible to record and playback sound without having to pay much for it, but by the same token it became all the harder for those who produced audio material to get paid for their work; the cassette made it possible for freedom fighters to spread the word, but in the same way made it just as easy for hatemongers and sectarians to spread their word. From the historian’s perspective, though, all such material is valuable for understanding the past, and a recording technology like the cassette enables us to quite literally hear the voices of those whose voices we could never have hoped to hear if the only people making recordings were those with economic and political power.

At the level of music—the preponderant form of audio material recorded on cassettes—there is an additional side to consider when thinking about the value of what is recorded on cassettes. The political, cultural, and economic determinants of what got recorded before the cassette era generally meant that the kind of music that was recorded was some combination of music acceptable to social and cultural elites, and music that had highly profitable commercial value. The democratization of recording meant that music that did not fit into these categories could finally be recorded and distributed. Wedding singers, practitioners of local musical forms that did not fit the cultural orientation of culture ministries and state broadcasting, artists producing musical forms that did not have enough of a following to attract a profit-motivated recording operation, and so on – such music could now be recorded. Musicians unable to get a contract with a recording outfit could now simply record their own tapes and distribute them through whatever channels were available to them, or make a demo tape to share without having to rent out a full recording studio. The neighborhood cassette shop, the cassette kiosk in the commercial part of town, the grocer and hairdresser’s shop, or even direct sale to audience members at gigs and weddings—these all became avenues to have your work heard and, for the artists, designers, and photographers involved in cover art, seen.

In this sense, the material recorded on cassettes is thus a broad archive of the social, cultural and political history of the period from the 1970s to the early 2000s; there was no format quite like it until digital audio recorders became somewhat affordable. Given that we’re unlikely to see large digitization projects initiated by state institutions or other well-resourced bodies in our countries in the global south, the main way material like this is likely to be preserved is through the work of small-scale collectors and collectives, like the Syrian Cassette Archives. Given the massive scale of how much material was recorded, the scale of such projects can only really hope to preserve a tiny proportion of what was made, but some is better than nothing at all, and time is not on our side.