Apparently, doing a halfway-decent cover version is grounds for a cheap money-grab.

The Romantics licensed their song "What I Like About You" for a cover version in Guitar Hero Rocks the 80's, but apparently something went wrong somewhere along the way.  Wavegroup Sound, who have made all the cover versions of the songs in the Guitar Hero series, did their usual job of mimicking the sound of the original, and The Romantics feel that it "has infringed the group's right to its own image and likeness."

There's no issue here about whether or not Activision and Wavegroup Sound, both named in the lawsuit, acquired proper licensing for performing the cover version.  The paperwork is there and signed, and the respective companies were perfectly within their rights to include the song they paid for in the game.  At issue is how close the Wavegroup Sound version is to the original.  No, I don't get it either, but maybe this quote from The Romantics's attorney Troy Horton in the USA Today article can clear things up-  "We're all for good commerce. We just want to share in it."