FILE - In this Feb. 4, 2007 file photo, Prince performs during the halftime show at Super Bowl XLI at Dolphin Stadium in Miami. Since Prince died, YouTube and other uploading sites have been flooded with hundreds of hours of the superstar musician's songs, concert footage, TV appearances and music videos. It's a sign that the notoriously tight copyright controls the artist maintained over his material is rapidly loosening, and raising hope that hardcore fans might someday hear the Holy Grail of Prince's music: unreleased recordings from the vault at Paisley Park. (AP Photo/Chris Carlson, File)