Photographer Bob Gruen spent decades capturing the lives and performances of rock stars of the '60s, '70s and '80s, including John Lennon, the Rolling Stones, Chuck Berry, Tina Turner — and many more.
Gruen put in many hours backstage, in studios and on the road, sometimes doing drugs and drinking until dawn with his subjects.
"I carried a little flask of cognac in my camera case. It was part of my equipment. That's the way it was in the '70s," he says. "I don't know how I survived, because I crave peace and quiet — but I actually thrive in chaos."