Answer:
There was the biggest outdoor rock fest ever, on August 15-18, 1969.
Thousands of people came to Woodstock (actually held near Bethel in upstate New York) to listen to the likes of Janice Joplin, Jimmi Hendrix and many others for 3 days of musical performances. This was a major display of the 1960s counter-culture (hippies) and anti-war movements. There was considerable use of illicit drugs.
Conditions were sunny and hot, but there was also rain that turned some of the concert grounds into massive mud pits.
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