Grateful Dead: The World's Best Rock Band, April 17, 1971

According to the LA Times, on April 18, 1971. the World's Best Rock Band is the Grateful Dead.  I agree.  For example, listen to Pigpen and the boys play Princeton University on the night before here
or here

The Grateful Dead’s invasion of Dillon on April 17, 1971 — Hell’s Angels motorcycle gang in tow — is famous among devotees for a quintessential performance of “Good Lovin’ ” by band member Ron “Pigpen” McKernan, then suffering from what would be fatal cirrhosis. “The concert was expensive, $10,000,” says Lockwood, a faithful Deadhead who treasures a cassette recording he made that night.

The band played until “well past midnight,” Lock­wood recalls, and “a substantial part of the audience, which was all students, was stoned out of their minds.” Concertgoers passed ­marijuana joints down the rows of seats, he says. According to legend, when a Princeton proctor demanded that ­shaggy singer Jerry Garcia extinguish his joint, Garcia snarled, “I’ll never play here again.” He never did.  https://paw.princeton.edu/article/play-song-me