"During his session with Led Zeppelin, in a former theater, the Dead showed up unexpectedly. At one point, Pigpen took a .22-caliber revolver from its holster and started firing into the seats.
“It absolutely freaked Zeppelin out,” Mr. Greene said in a video interview with the Morrison Hotel Gallery in Manhattan, which exhibited his photographs in 2012. “They didn’t pay me. They were just like, ‘Those Westerners and their guns.’”
“This is my best story,” he added. “The day the Grateful Dead freaked out Led Zeppelin.”
Some of Mr. Greene’s photographs were used on album covers. One of the best known was a group portrait of Jefferson Airplane that became the cover of the band’s second album, “Surrealistic Pillow” (1967), which included the hits “White Rabbit” and “Somebody to Love.”"