How about the great Electric Light Orchestra? They did some REALLY great things in the time they were around, then came back and DID IT AGAIN! I'd LOVE to see earlier shows at that for "On The Third Day."

PS - How about more Pink Floyd... and make that the EARLY Fillmore show that Syd detuned his guitar and setting the crowd off, I would kill people to hear it. (Mainly because back then, no one took tape recorders to gigs, especially 'lesser known' artists, which they were at the time.)