Duff McKagan of Guns N’ Roses just graduated from high school last week. He got his diploma at 48 years old. Duff is a smart guy; he writes for ESPN and Playboy and runs a finance firm for rock stars but he didn’t have the formal education of some rock stars. Here are some of the most educated rock stars out there.

Brian May of Queen has a Ph D in Astrophysics, Jim Morrison had an IQ of 149, Art Garfunkel has a Master’s from Columbia, Tom Morello graduated from Harvard, Dexter Holland from The Offspring was a Ph D candidate at USC, Rivers from Weezer also graduated from Harvard so did Michael Einzinger from Incubus, and Gene Simmons has a Ph D in education and was a teacher for several years before strapping on the KISS makeup.