Quicksilver Messenger Service is an American psychedelic rock band, formed in 1965 in San Francisco.
Quicksilver Messenger Service gained wide popularity in the Bay Area and, through their recordings, with psychedelic rock enthusiasts around the globe and several of their albums ranked in the Top 30 of the Billboard Pop charts. Although not as commercially successful as contemporaries Jefferson Airplane and The Grateful Dead, QMS was integral to the beginnings of their genre. With their jazz and classical influences, as well as a strong folk background, the band attempted to create a sound that was individual and innovative. Member Dino Valenti drew heavily on musical influences he picked up during the folk revival of his formative musical years. The style he developed from these sources is evident in Quicksilver Messenger Service's swung rhythms and twanging guitar sounds
In 2006, Gary Duncan and David Freiberg launched a 40th-anniversary Quicksilver celebration tour