When I first saw it on the conference portion of the SXSW website, I knew I'd be there: a conversation between Thurston Moore, the singer and guitar player in pioneering art-rock troupe Sonic Youth, and Steve Reich, the heralded American minimalist composer whose percussion masterworks include "Drumming" and "Music for 18 Musicians." Moore, at 49, is arguably the wisest elder of indie rock, his band Sonic Youth having cranked out some 16 albums since forming in the early 80's, while Reich, who is 72, is arguably the greatest living American composer, having influenced a subsequent generation of artists bridging classical music, rock, electronica, and even hip-hop.