"He asked artists to do their thing somewhat simultaneously. He quickly sketched out a layout with the audience surrounding the performers and created the timing for the participants. They were not told what to do, just where and when.
"The poet Charles Olson read, probably on a ladder. Cage delivered a lecture he had written earlier for Juilliard. Cunningham improvised a dance. Avant-garde virtuoso David Tudor played something or other on the piano. Robert Rauschenberg, who had been a student of Albers, hung his white paintings and maybe a black one. There were projections of film and a painting by Franz Kline overhead.
"This is widely credited as having been the first Happening and the inciter of performance art. "
Mark Swed in the Los Angeles Times looks at John Cage's time at Black Mountain College.