First recorded by Barry McGuire (1965).
Hit version by The Mamas & The Papas (US #4/UK #23 1966).
From the wiki: “According to John Phillips in a Bravo documentary, and Michelle Phillips in an NPR piece, the song was written in 1963 while they were living in New York. He dreamed about the song and woke her up to help him write it. At the time, the Phillipses were members of the folk group The New Journeymen which would evolve into The Mamas & the Papas.
“The Mamas & The Papas earned their first record contract after being introduced to Lou Adler, the head of Dunhill Records, by Barry McGuire. In thanks to Adler, they sang the backing vocals to ‘California Dreamin” on McGuire’s album, This Precious Time. The Mamas and the Papas then recorded their own version, using the same instrumental and backing vocal tracks to which they added new vocals. (McGuire’s original vocal can be briefly heard on the left channel at the beginning of the record, having not been completely wiped.)”
“After gaining little attention in Los Angeles upon its release, Michelle Phillips remembers that it took a radio station in Boston to break the song nationwide. In March 1966 the song peaked at #4 on the Hot 100. Sharply dividing the popular music market that month, rivals ‘California Dreamin” and ‘Ballad of the Green Berets’ eventually tied for the #1 record of 1966. ‘California Dreamin” became a signpost of the arrival of the nascent counterculture era, and is ranked #89 on Rolling Stone magazine’s list of The 500 Greatest Songs of All Time.”
The Mamas & The Papas, “California Dreamin'” (1966):