Jimi Hendrix sat in with Englebert Humperdink one night (he was touring a bill WITH E.H. and a musician needed to be replaced one night). I'm not sure if this was the Jimi Hendrix Experience or an earlier band.
From what I've read and seen, Jimi Hendrix was going to die young through drugs or exhaustion because that guy played any gig at all hours with any one on both sides of the Atlantic and both coasts of America. I think the drugs were just making it possible for him to wake up and go to sleep.