The event was notable not only because of Plastic Ono Band's relatively last-minute addition to the bill, but for two other incidents as well: 1) the creation of the "lighter" phenomenon, and 2) the Alice Cooper chicken rumor.
Before the Plastic Ono Band's set, MC Kim Fowley asked the crowd to welcome the Plastic Ono Band to the stage by lighting a match or their lighters. It stuck. And now we do it at every concert we go to during the power ballads.
As for Cooper, this was where the rumor started that he bites heads off of chickens. During his set someone threw a chicken on stage. He threw it back off. Cooper says it was the front row audience members who torn the chicken apart, not him.