In the couple of months that I've actually been serious about my Twitter grind I've only come across a couple of music-related ones that are actually interesting. By far the best has been ?uestlove's. People always refer to him as "?uestlove from the Roots," but he's just as active in his production work and DJing as he is drumming. So his Twitter has a lot of random travelogue-type material--much of it fast food related--and behind-the-curtain entries that can be glitzy, e.g., "why is it that whenever the big A cats come to do vocals (Kels MC, JT, or Timbo) then all of a sudden i see: wine, cheese, fruit and flowers," or fascinatingly mundane, e.g., "6:05 am. on a roll. 4 beats made. gonna squeeze one more out." He's also started putting audio online, and it's not just dorky studio-guy stuff like drum comparisons. Last week he posted a batch of unreleased Lauryn Hill songs.
(If you have any recommendations for music tweets I should be following, let me know. I'm here.)