School of Rock
School of Rock offers music classes, camps and workshops perfect for musicians of all skill levels who play guitar, bass, drums, keyboard, and vocals.
My six year old attends the School of Rock (there are several Bay Area locations). He's in the Rookies program which they get experience with guitar, bass guitar, keyboard, drums, and vocals. They don't have to pick an instrument, and get to play around with all of them and learn simple songs. Once he completes this program he will move into a single instrument (Rock 101 program). He's leaning towards guitar too.
My other kid is already in the Rock 101 program and on keyboard.