Quicksilver Messenger Service consists of , Bobby (bass), David Freiberg (bass, keyboards, guitar, vocals), Gary Duncan (guitar, vocals), Greg Errico (drums), Jimmy Guyett (bass), John Bird (guitar, vocals), Michael Lewis (keyboards), Tony Menjivar (percussion).
Quicksilver Messenger Service was one of San Francisco's original psychedelic bands in the 1960s, along with The Grateful Dead, Jefferson Airplane and the rest.