The April 29 release of the much-anticipated "Grand Theft Auto IV" could beat out "Halo 3" as the best-selling videogame of all time. Early predictions peg first week sales at around $400 million, to Halo 3's $300 million. Focusing on units over revenues, Halo 3 moved 5 million games the first week, while UBS analyst Ben Schachter points to 7-8 million for "Grand Theft Auto IV," with upwards of 10.5 million units by the end of the year.

The matchup is a little apple-to-oranges, as "Halo 3" was an Xbox 360 exclusive while "Grand Theft Auto IV" will be available for both the 360 and the PlayStation3.

The music industry cares about this because "Grand Theft Auto IV" will carry a massive soundtrack of licensed music. The game's developer Rockstar Games won't disclose the exact number of tracks, but each previous installment of the series set a new record. The newest title also allows users to tag songs from the soundtrack for later purchase on the Amazon MP3 digital music service.