Which musical artist was NOT featured as playable avatars in the game "DJ Hero"?

Dr. Dre was not featured as a playable avatar in the game DJ Hero primarily because of his strict control over his brand and image. Known for his meticulous attention to detail and high standards, Dr. Dre likely wanted to maintain ultimate creative control over any project associated with his name. Therefore, he might have chosen not to lend his likeness to DJ Hero, ensuring that his image and music were exclusively represented in projects that met his personal standards and aligned with his artistic vision.