Why she's on the list:
Whitney Houston's done it all, including music, movies, modeling, and [INSERT BLATANTLY OBVIOUS DRUG JOKE]. She's never been in a band game, though. Obviously she didn't make rock 'n' roll music, but there are a number of pop and R&B acts in Rock Band, from Otis Redding to Lady Gaga. Before her Hollywood digression and depressing downward spiral, Houston was the defining diva of the 1980s and early 1990s, selling over 100 million records.
Why she may not be in the games:
Whitney's fall was fast and hard, and today it's easy to forget how massively popular she once was, especially as her R&B crown was quickly seized by a near-contemporary who could oversing even worse than she could. Who could that be? We'll see when we get to #5 on our list.