MOUNT PLEASANT, Mich. (AP) – Speaking at Central Michigan University’s commencement Saturday, Rolling Stones keyboardist Chuck Leavell (luh-VEL’) sent graduates off into the real world with a joke. He posed the question: What’s the difference between a musician and a municipal bond?” According to Leavell, the correct answer is, “A municipal bond matures and makes money.” Leavell says he learned to play piano by listening to his mother play and she never had any formal training. He told the graduates the pursuit of excellence will take them to wherever they want to go in life. Leavell was also presented with an honorary doctor of music degree at the event.