The Beach Boys' Mike Love's new memoir Good Vibrations is due out Sept. 13

More than five decades after forming as a band, the Beach Boys are still having fun, fun, fun.

Frontman Mike Love tells PEOPLE that he hasn’t lost “sight of the overwhelming positivity of [the band’s] music,” even after countless performances and more than 100 million records sold.

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But touching the hearts, and ears, of a new generation doesn’t overshadow dark days from the band’s past – details that Love shares in his upcoming memoir, Good Vibrations, which is excerpted exclusively in this week’s issue of PEOPLE, on newsstands Friday.

In an exclusive trailer for the book, the father of eight says of his time in the spotlight, “I’m a person who believes that anything is possible.”

Love joined his cousins Brian, Carl and Dennis Wilson and high school pal Al Jardine to create the Beach Boys in 1961. In Good Vibrations, he reveals that various bandmates battled drugs and personal demons.

For more from Mike Love’s memoir, pick up this week’s issue of PEOPLE, on newsstands Friday.

Namely, the 75-year-old says that Dennis forged a friendship with ex-con and commune leader Charles Manson ahead of the latter’s brutal August 1969 killing spree.

Dennis, who drowned in Marina del Rey, California, on Dec. 28, 1983, had allowed Manson into his life and home, says Love.

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In fact, one of the bands’ songs – “Never Learn Not to Love,” released on the B-side of a 45 in 1969 – was actually originally penned by Manson under a different name and tweaked by Dennis, who Love writes was inexplicably under the murderer’s spell.

Their relationship ultimately fell apart, and Dennis felt lasting guilt for the association, Love says.

Despite ties to one of American history’s darkest moments, Love tells PEOPLE, “We’ve had our ups and downs but our music has always transcended the negatives and the hardships.”

That’s a message Good Vibrations conveys. From the early days and Pet Sounds to late-’80s hits like “Kokomo,” Love’s memoir covers all aspects of his life.

As Love says in the book trailer, “I guess if you can make up songs out of the air and eventually stand in front of a half million people and have people give you a standing ovation before you do anything, then your vision of reality and possibility is different than maybe a lot of people.”