He's one of the most successful songwriters and performers in the history of classic rock -- both as a solo artist and as a member of one of the genre's most popular bands. Can you recognize him from this very serious-looking yearbook photo?

You need a few more clues? That's fair. Here goes: depending on the occasion, you might find him leading a band or keeping things running smoothly from the back of the stage. He's an outspoken activist both for artists rights and the environment, and if you want to re-arrange one of his songs you REALLY should ask for permission first.

Think you know which famous rock star we're talking about? Click below to find out!