When the group was just starting out in 1965, their friend Barry McGuire helped them get a contract with his record label, Dunhill Records. McGuire recorded the first version of the song with The Mamas & the Papas as his backing band and a harmonica solo instead of a flute. It was going to be used as the follow-up single to his hit, "Eve Of Destruction
." The Mamas & The Papas then decided to record it on their own, with Denny Doherty (the other Papa) singing lead and some chord changes he came up with after consulting the session guitarist, P.F. Sloan, who had him listen to "Walk - Don't Run
" by The Ventures. The results were impressive, and Dunhill Records agreed to use it as their first single, holding off on McGuire's version so there wouldn't be competition from an established artist.
The group's first single was "Go Where You Wanna Go
," which didn't "go" anywhere and was pulled to focus on "California Dreamin'," allowing The 5th Dimension to score their first chart it with that song a few months later. When "California Dreamin'" caught on, listeners wanted to hear more from The Mamas & the Papas, so radio stations started playing "Monday, Monday
" off the album. When that song was released as a single, it quickly shot to #1 in America.
The group had a string of hits until 1968, when they split up. They reunited occasionally until 1974, when Mama Cass Elliot died of a massive heart attack due to her poor health and eating habits.