Gracenote runs the service that automatically fills in song names, musicians, and album names when you rip a CD to your PC's hard drive. Without it, we'd be stuck spending years entering CD track data manually. But the company is no longer without competition — and it just lost a big client to a rival. Gracenote has been discreetly dropped by RealNetworks. A tipster alerts us that RealPlayer and Rhaposdy are now using All Media Guide's identification service, Lasso. Real joins a growing list of AMG adopters, including Sony and Apple. It's no surprise that the music services, facing thin margins, are shopping around.