I have a few.
Bjork: Vocals
Jonny Greenwood: Guitar
Flea: Bass
Aphex Twin: Electronics
Jim Chamberlin: Drums
I really like this one.
Peter Gabriel: Vocals
Steve Howe, Robert Fripp and David Gilmour: Guitar
Tony Levin: Bass and Chapman
Bill Bruford: Drums and Percussion
Rick Wakeman: Keyboards
Ray Shulman: Violin
Mel Collins: Sax and Flute
^ Prog supergroup.
Jimi Hendrix: Guitar and vocals
Greg Lake: Bass and vocals
Keith Emerson: Keyboards
Carl Palmer: Drums
It could have happened. Its funny to imagine what it would have been like if it was Hendrix singing Karn Evil 9 and dueting on guitar with Emersons synthesizers.