"Writing/Talking about music is like dancing about architecture."
I first read this in the liner notes to something from Laurie Anderson (United States — I think). I recalled her attributing it to Steve Martin.
Since then I've also seen it variously attributed to Frank Zappa, David Bowie, David Byrne, Robin Hitchcock and Elvis Costello.
Anyway, Scott adds to the list of suspects, including (among others) John Cage, Thelonius Monk, William S. Burroughs and Martin Mull.
While it's kind of apt and delightful that a quote about the limits of language should be so difficult to trace, the copy editor in my head insists on finding a citation.