If there has been any unifying idea or theme to music in the 00s, it is surely the squashing, the shriveling, the incredible shrinking of music itself. Out went the album, in came the single (and the ringtone!). As our attention spans raced toward :00, it sometimes felt like we had traded in big anthems and sweeping melodies for fragments, the hook, the bits and pieces. Maybe that's all that we have left now that everyone controls their own playlist. But is that so bad? At this moment in pop history, it seems appropriate to look at music, and enjoy it, for the parts as well as the sum total. We're not out to create a mashup (DJ Earworm did that well enough, thanks), but we've been taking a good look at the best song bits of the year.

Check out our picks for the best work of 2009 in eight key categories — are these just eight great ideas? Pieces of one imaginary masterpiece? Or a little of both?