Quicksilver Messenger Service is an American psychedelic rock band, formed in 1965 in San Francisco. Of all the bands that came out of the San Francisco area during the late 60s, Quicksilver Messenger Service typified the style, attitude and sound of that era. Dogged by early personnel changes, the original band in 1964 comprised of vocalist Dino Valenti, guitarist John Cipollina, David Freiberg on bass and vocals, Jim Murray on vocals and harmonica, and drummer Casey Sonoban.