A couple of years ago, one of the angriest comment threads ever on Music Thing concerned a bunch of students in Aberystwyth who bought a piano on Freecycle, put it on a beach, burned it, and said it was art. Today, YouTube is stuffed with people being mean to pianos. Damn, you must have had some bad piano teachers...
piano destruction was of course very important in the fluxus movement in the 1960ies. here's a great video of sonic youth playing george maciunas' composition "Piano Piece #13 (for Nam June Paik)" from 1962, one of the key pieces of piano destruction music (and obviously by far more that just piano destruction):