Call it the sideman's revenge fantasy: You're paying your dues in the shadow of a spotlight hog, but one day you'll get a great song out of it. Tori Amos turns that one on its head with "Not David Bowie," from her new five-disc box set, A Piano: The Collection. The crunching tribal-industrial beat and fuzzy, grinding organ are anything but subtle, and in just about the bluntest terms she's capable of, Amos turns her fury on a nameless sideman. If he's wondering why he never made it on his own, she's got some suggestions. It could be mediocrity, unoriginality or a lack of gratitude. Could be booze. It ain't her foot on his neck, though. "Take me back to the fact that you're still blaming," Amos spits, "but I am not the reason you are not David Bowie." Speculation started seconds after the song leaked; blogger/uber-fan Molly Knight fingered guitarist Steve Caton, who put in 10 years by Amos' side before falling out of her orbit in '99. So let's run with that. Let the faithful dish about backstage misbehavior; Amos knows where his real weak spot is, and she goes there: "You were good once/ Now you're filled with bitterness/ And it is what it is." Who'd dare argue?