who keeps dropping references to Billy Idol lyrics. He's forced to turn to therapy, with his therapist played by none other than Joan Jett. The "Rebel Yell" singer's last full-length was Kings ...

Billy Idol and Joan Jett are teaming up for a summer tour ... in which he can’t go anywhere without having somebody quote his own lyrics to him. Guess who turns up as a psychologist?

Joan Jett took the stage to thunderous applause, singing Nevermind’s “Territorial Pissings” while a sweaty Grohl banged away in the background. (She missed a couple of lyrics, but who cares?