"I had wandered off the reservation and gotten into John Cage and avant garde music." That was how Welsh musician John Cale, on Desert Island Discs, described his move from music college into the New York music and art scene that brought him into collaborations with Lou Reed and Andy Warhol. TESTeacher has an interest in John Cale because next week our music Subject Focus pages include an article on how students are rising to the challenge of the music of his mentor, John Cage. So we were delighted to be able to get information on Cale's tastes from the excellent facilities of the BBC's websites. Copyright forbids full replay (although other radio programmes are available) but you can have a fascinating trawl through the favourite tunes of a range of celebrities.