To steal an American Idol-ism, a diva is a triple-threat. Lady Gaga's just threatening.
"Take a bite of my bad girl meat ... Show me your teeth / The truth is sexy" are some lines announcing that her inner freak's been unleashed on The Fame Monster. No longer content to "Just Dance," Gaga wants to show us the dark side of celebrity. It sounds the same as the bright side; just add sadomasochism.
One can't get a handle on Gaga from the music alone. A true 21st-century girl, she's a multi-platform artist, replete with her own YouTube channel and elaborate videography, which is a bit Matthew Barney, a bit Vogue and a bit Marilyn (as dreamed up by both Norma Jean Baker and Brian Hugh Warner). It's all arresting and repellent, inanely avant-garde but also surprisingly pornographic, maybe because the truth is so "sexy."
As for the music, one listener's reaction to hearing The Fame Monster out of context was, "Is this Cher?" I can see the listener's point. She's doing nothing that hasn't been done before—and arguably, better—by others. She recreates Madonna's "La Isla Bonita" on "Alejandro," and her monstrous throat-clearing on "Bad Romance" couldn't exist without Polly Jean Harvey. The music doesn't seem to assert any definable persona. It needs the videos to do that.
But Gaga's all guile. At once fractured and mighty, her heart may have been eaten by man-as-monster, but she can function just fine without one, thanks. She's now the diva as corpse bride—very threatening.