Executive Meddling: Several songs were purportedly chosen because Nintendo of America president Reggie Fils-Aime liked them. In addition, many rumors of a sequel exist purely based on the fact that Reggie was apparently quite fond of the game. Not that him getting us a sequel would be a bad thing.
In fact, it seems that "September" and a Jamiroquai track have to be in every music game Nintendo has some hand in, being as they are in EBA, Donkey Konga and... well, that's it.
"September" and "Material Girl" are also in Wii Music.