This site may have become a clearing-house for classical hilarity, but there's a fair amount of in-depth analytical commentary out there in the bløgösphêré, as we like to call the classical corner of the web. See, say, Jeremy Denk on the Kreutzer Sonata or Kyle Gann on Glenn Branca. The latest analytic blog I've come across is Unconquered Sound, which has a post called "fun with hemiolas" and what appears to be the definitive explication of "Let It Snow." For something much less technical, read Corey Dargel's thoroughly absorbing account of new trends in songwriting at NewMusicBox.
