Musicassettes
 

Philips Industries had invented and launched a new reel-to-reel audio cassette (aka compact cassette and later the musicassette), enabling music to be recorded and played anywhere on a small battery-operated portable machine. As a result, in 1966 Philips Records started to release pre-recorded music, both popular and classical in this format. The launch was managed in the UK by Walter Woyda who had joined Philips from the Keith Prowse agency the previous year. Sales were modest to begin with and because musicassettes were a new innovative sound carrier, no other record company wanted to risk setting up a factory to manufacture its own product, leaving it to Philips to live or die with this new format. So Philips started to manufacture pre-recorded cassettes for most of the other UK music companies including EMI, CBS, Pye, Warner Brothers and Reprise. Until the format proved itself, it all rested with Philips to make it a success. (Early in the 1970s, there was a promotion to launch another tape format: 8-track cartridges in the UK, but it didn't catch on with the British public despite being hugely popular in the U.S. and production ceased in 1974).

In the event, sales of music cassettes never really took off until Sony introduced the ‘Walkman’ in 1980, when the quality of the sound reproduction coupled with this new smaller, lighter player proved a huge success. So for a short while at least, sales of pre-recorded cassettes started to overtake those of vinyl LPs, but with the compact disc format soon to be launched, that success was short lived.

http://www.theregister.co.uk/2013/08/30/50_years_of_the_compact_cassette/