There are more than a few reasons digital rights management (DRM) has been largely unsuccessful. But the easiest way to explain to a consumer why DRM doesn't work is to put it in terms he understands: "What happens to the music you paid for if that company changes its mind?" It was one thing when it was a theoretical question. Now it's a historical one. Rhapsody just had the next in a line of DRM music services to go–this week the company told its users than anyone with RAX files has unil November 7 to back them up in another format or lose them the next time they upgrade their systems.