The 1960's brought the world the Beach Boys' sunny Southern California music. But there was a darker side to all that surfing and dancing. 

Mike Love, a founding member of the music group, recalls the band's association with Charles Manson, who pushed his followers to murder in the late 1960s, in his new memoir, "Good Vibrations." An exclusive excerpt of the book was published in this week's issue of People magazine.

The Beach Boys sold more than 100 million records and have been inducted into the Rock and Roll Hall of Fame. "I never lose sight of the overwhelming positivity of our music," Love, 75, told People. "I still see it every night in the faces of the people who come to our shows." 

But before the worldwide fame, band member Dennis Wilson became friends with Manson and his followers. In August 1969, they left seven dead, including Sharon Tate, the pregnant wife of director Roman Polanski. 

Wilson meet Manson after picking up two young women hitchhiking on Sunset Strip in Los Angeles. They urged him to meet their "guru," who happened to be Manson, then an aspiring rock star. Wilson was won over by Manson's song writing, Love said. At one point, Manson and his family members moved into Wilson's Sunset Boulevard house. A year later, the group carried out Tate's murder. 

"My cousin's interest in Manson now seems inexplicable," Love writes in his memoir, "but in reality Manson tapped into parts of Dennis that make it all too explainable." 

Love said he and another Beach Boy, Bruce Johnston, were hanging out at Wilson's home one time when Manson take out some LSD and was "orchestrating sex partners." Love tried to leave, but Manson told him, "you can't leave the group."

Johnston later said of Love: "If Brian [Wilson] was the shy, introverted guy in school, then Mike was the cool guy who'd tell him how to ask girls out, and that's what Mike did for Brian's music."