They are not all idiots in Hollywood. Peter Weller and Brian May come to mind.
Some others are Jeff Baxter from Steely Dan, who has worked as a defense consultant, and John Tichy, a guitarist with Commander Cody. Tichy had a Ph.D. already when he joined the group and later became head of the Department of Mechanical, Aerospace and Nuclear Engineering at Rensselaer Polytechnic Institute. And then there's Woody Paul, the fiddler for Riders in the Sky, who holds a Ph.D. in physics from MIT.