Last year, doctors told John Mayer it could be years before he sang again. “There was not a lot of hope,” says the singer, who’d already been through failed surgery to repair a granuloma in his throat. “They said cancer would have been easier to get rid of.”

But a second round of surgery in August worked, and on January 16th, Mayer played his first set in two years at a benefit in Bozeman, Montana, for the firefighters who battled the wildfires that destroyed 12,000 acres near the singer’s home last summer.

Mayer sounded raspy but overjoyed jamming on an eight-minute version of last year’s “If I Ever Get Around to Living.” Click here for an exclusive online Q&A from rollingstone.com.