Digital technologies disrupted the music industry in the 21st century. But an invention by Philips, launched in 1963 at the Berlin Radio Show. changed forever the relationship between consumers and music. The cassette – magnetic tape on two spools housed in a hard-plastic shell – could record music or spoken word, in cassettes of 60, 90 and 120 minutes.

As the decade went on, more and more manufactures began making machines that could play such tapes and they became a global phenomenon. The 1970s arrived ushering in the era of boom boxes – portable players – and the Sony Walkman, both personal and portable. Cassette players made their appearance in cars from 1968.

A self-made mixed tape – often made by rushing to the record button as the song came on the radio – expressed individual musical taste, an audio badge of identity and now a fertile ground of academic study. As a fascinating new book, A History of Intellectual Property in 50 Objects (Cambridge University Press), points out, the ability to so easily self-record music immediately raised the question of copyright – all those home recorders were breaking the law.

In the UK, Lord Templeman, charged with ruling on copyright issues in 1988, admitted it was impossible to implement the law that was observed in the breach more than in the observance.