An interesting introductory article from Jason Feinberg, summarizing the challenges facing the music publishing industry:
The pioneers of the music industry couldn’t have seen this coming in their wildest dreams. When publishers were selling sheet music in the late 1800s, the idea of people privately sharing their product, independent of location and physical constraints, would have seemed ridiculous. But now record labels have been decimated by the digital shift, and are rethinking their entire business model to survive.