Rosemary Butler began her career playing bass and singing in an all-girl band named the Ladybirds. The band appeared on several LA area television shows before opening for the Rolling Stones in 1964. She then joined heavy rock band Birtha who released two albums for Dunhill. After they split in 1973 she became a popular back-up singer in the late 1970s and early '80s. Her vocals were featured on Bonnie Raitt's album, Sweet Forgiveness, on songs "Gamblin' Man", "Runaway", "Sweet Forgiveness", and "Two Lives."
She sang in Japanese motion picture soundtrack Dirty Hero (), its title track "Riding High" in 1982.
She was also Co-Contractor of the 100 voice choir on Neil Young's album Living With War
She has vocal coached numerous famous voices.
She cofounded "The National In Choir" an LA based volunteer holiday choir with singer/lyricist Deborah Pearl.