Let's not forget that in addition to the list by StopTheViolins, Robert Johnson died a mysterious death at the age of 27. He was one of the most influential and innovative guitarists back in the day, and is often referred to as the "king of the delta blues."
This list also includes one of the most influential rock drummers of all time: Keith Moon of The Who. He influenced many young drummers, including his friend John Bonham of Led Zeppelin, who died at the age of 31. Bonham would later quip, "I'm the greatest Keith Moon type drummer in the world!" They were both known for their on-stage antics, and their hard-hitting drum solos as well as their collections of fine cars. They helped to define a hard rock sound that many have tried to reproduce.