Dear Apple: Buy this, and put it in the next iTunes
From Tech Crunch’s MusicBox: a truly powerful visualization of your music library: “The idea behind MusicBox is that it analyzes every song for not only written metadata (artist, genre) but also beats per minute, length, tone, and a whole bunch of other semi-tangible quantities (check out the demonstration video). It then organizes them based on whatever axes you choose — looking for your short, fast-paced songs? They’ll be on the upper left if you tick ‘song length’ and ‘tempo.’ Want those songs that change up their beat? They’ll be on the left if you just tick ‘time signature stability.’ It even puts together graphic previews of the songs, much like what I found when using a spectrum analyze.” [Editor's note: Make sure you watch the demonstration video]