Diva Depletion

The other half and I have seen our fair share of divas perform live. I'm making a list (and checking it twice?) about who we've seen; and who I know I need to see to make the list more complete. I need input on who I might not be aware of to make the ultimate, super-duper, crazy diva list. There really cannot be that many left. Help me out here. And, I'm talking about all time diva shit; not some Jessica Simpson type who has yet to earn the diva title. Could be later, but certainly not now. Get me?

Madonna--Yes (3 times)
Janet Jackson--Yes (1 time)
Diana Ross--Yes (1 time)
Sandi Patty--Yes (4 times?)
Barbra Streisand--Yes (1 time)
Celine Dion--Yes (1 time)
Stevie Nicks--Yes (1 time...w/ Fleetwood Mac; does that count?)
Whitney Houston--NOT YET
Mariah Carey--NOT YET
Elton John--NOT YET
Aretha Franklin--NOT YET
Cher--NOT YET

Who's missing?