Could be worse, I'm stuck with Imagine on Expert Bass
It could be worse still: mine is Need You Tonight on Hard Pro Keys a score of 15,120. It's downright embarrassing. I'm ranked on about 14 songs and have gold stars on a handful of them - so I wish they'd take total score and difficulty into account when determining my Signature Performance. I'm much more proud of my performances on virtually any other song than this one.
Obligatory DLC Wishlist:
The The - The Cure - Depeche Mode - Tori Amos
Oingo Boingo - Tones On Tail - Tom Waits