Scott McKenzie according to Wikipedia

McKenzie grew up in North Carolina and Virginia, where he became friends with the son of one of his mother's friends, John Phillips. In the mid 1950s, he sang briefly with Tim Rose in a high school group called The Singing Strings, and later with Phillips, Mike Boran and Bill Cleary formed a doo wop band, The Abstracts. In New York, The Abstracts became The Smoothies and recorded two singles with Decca Records, produced by Milt Gabler. In 1961 Phillips and McKenzie met Dick Weissman and formed The Journeymen, which recorded three albums for Capitol Records. After disbanding The Journeymen in 1964, they discussed forming a group called The Mamas & the Papas. McKenzie wanted to perform on his own, so Phillips formed the group with Denny Doherty, Cass Elliot and Michelle Phillips, his second wife. The group soon moved to California. Two years later, McKenzie followed from New York and signed with Lou Adler's Ode Records. Phillips wrote and produced "San Francisco (Be Sure To Wear Flowers In Your Hair)" for McKenzie, which was released in 1967. John Phillips played guitar on the recording and Michelle Phillips played bells. The bass line of the song was supplied by session musician Joe Osborn. It became a Top 10 hit in the United States and a number one in many other countries.
McKenzie followed the song with "Like An Old Time Movie", also written and produced by Phillips, which was a minor hit. His first album, The Voice of Scott McKenzie was followed with an album called Stained Glass Morning. He stopped recording in the early 1970s and lived in Joshua Tree, California and Virginia Beach.
In 1986, he started singing with a new version of The Mamas and the Papas. In 1988 McKenzie co-wrote the Beach Boys hit "Kokomo" with Phillips, Mike Love and Terry Melcher; as featured in the Tom Cruise movie, Cocktail.
By 1998 he had retired from the road version of The Mamas and Papas, and currently resides in Los Angeles.

Source: Wikipedia