May 29th marks a particularly enjoyable anniversary in the history of the Grateful Dead, as the band’s 1971 concert at the Winterland Arena would forever be known as the “Acid Punch Show.” While the Dead’s musical performance was certainly memorable – as were many from this golden era of the band’s career – it was the crowd that makes this show that much more memorable.According to the story, some people snuck in two garbage cans full of spiked cider in through the backstage doorway, with a guard’s permission, and passed them around inside the venue. With New Riders Of The Purple Sage and more on the bill, the psychedelic grouping certainly inspired the acid test of the evening. Thus, the “Acid Punch Show” was born.A number of people describe the scene outside the venue from the night, with one particularly poignant quote to summarize the rowdy affair. A user named “Saint Michael” on Dead.net says, “[my] starkest memory was coming out of the show and seeing this naked guy on top of a car howling at the moon with San Fran’s finest standing there laughing with each other waiting for him to come down.” What a party!On the other side of things, 21 people were unfortunately hospitalized after unknowingly drinking some of the cider and experiencing hallucinations. While the people were all fine in the end, promoter Bill Graham did briefly run into trouble with the city for this stunt. Fortunately for Graham, no one was ever able to tie the “Acid Punch” to the venue itself, and the case was dropped.Without further ado, sit back, relax, and raise a glass of punch (with or without LSD – that’s up to you) to the storied “Acid Punch Show” from May 29th, 1971. Incidentally, this was also the first time the Dead played Chuck Berry’s “Promised Land.”The Archive.org recording can be heard below.