[bilky asko]

As Techmoan has shown us on Youtube over the years, there was a wide variety of long playing endless loop cartridges on the market for various industries between the 60's & 80's. BBC Radio even used one type for jingles. I'm surprised BBC Presentation didn't just get one of those as they were designed to just sit in a room playing music continually with minimum maintenance.

I'm not sure the kind of tape that would hold enough music for this situation would be anywhere near broadcast quality.