Scott McKenzie, who sang "San Francisco (Be Sure to Wear Flowers in Your Hair)", died Saturday at his home in Silver Lake at 73.
The song, released in early 1967, helped give San Franciso its reputation as a center for hippie culture and self-realization.
According to McKenzie's website he had suffered from Guillain-Barre Syndrome since 2010, and had recently been hospitalized after a possible heart attack.
A member of the early 1960s vocal group the Journeymen, McKenzie reportedly declined an invitation to join the original Mamas and Papas.
In 1967, he did agree to sing the Papa John Phillips composition "San Francisco," and immediately found himself thrust in the limelight, something he did not always enjoy.
As his website notes, he "dropped out" and moved to Joshua Tree in 1970 and, eventually, Virginia Beach, Virginia.
That's where he still was was in the late 1980s when Phillips invited him to join the Mamas and Papas after an original member left.
About that same time McKenzie also co-wrote the Beach Boys hit "Kokomo" with Philips, Mike Love and others.
After retiring, McKenzie lived in LA and became very active on Facebook, engaging with friends and fans through his illness.
His Facebook profile includes quotes from Czeslaw Milosz, Mark Twain, Oscar Wilde and George W. Bush.
The Los Angeles Times reports he had no surving family, but his Facebook profile shows him in pictures with loving friends.
No word yet on a memorial.