There's a long list of rock musicians who'd love to have Eddie Van Halen in their band, but only a few of them have the means to actually make the invitation in person.
Do you believe in ghosts? More to the point, do you believe the ghosts of dead rock stars hang around concerts where their songs are being played? If so, then add Ronnie James Dio to the list of possible apparitions -- because according to at least one witness, he popped up (quite literally) at a Last in Line show this weekend.