Some rock stars are literally working around the clock.
Sometimes we don't realize that our favorite songs have been around longer than we thought.
When these stars weren't acting, they were singing.
Take a look at 11 of our favorite museums devoted to rock groups, classical composers, and more.
Maybe they didn't fit the tone of the film they were supposed to appear in. Maybe the director just couldn't find a place for them.
We've all heard these classic pop and rock hits a thousand times. But even if you know all the words, do you know what they were about?