Country pop legend Glen Campbell has died after a battle with Alzheimer’s Disease. He was 81.

GLEN CAMPBELL DEAD AT 81

The singer, songwriter, and guitar player was known for fusing the genres of country and pop. He was responsible for such Top 40 hits such as “Rhinestone Cowboy,” “Wichita Lineman,” and “By the Time I Get to Phoenix.” In total, he made that list 21 times. Campbell sold over 45 million records, even beating out the Beatles in 1968.

“It is with the heaviest of hearts that we announce the passing of our beloved husband, father, grandfather, and legendary singer and guitarist, Glen Travis Campbell, at the age of 81, following his long and courageous battle with Alzheimer’s disease,” a statement released by his family read.

Campbell became a public face of Alzheimer’s when he allowed a documentary to be made of his final tour in 2014, called I’ll Be Me. “He had that beautiful tenor with a crystal-clear guitar sound, playing lines that were so inventive,” shared rocker Tom Petty. “It moved me.”

Campbell was born in Arkansas in 1936, the seventh of 12 kids in a sharecropping family. He started playing guitar at a young age and fell in love with jazz guitarist Django Reinhardt. He dropped out of school at 14 to pursue his career in music. By 1962, he had solidified himself as one in the Wrecking Crew. And by 1963, he had been featured on 586 cuts for songs. In the 60s he appeared in the Byrds “Mr. Tambourine Man,” Elvis’ “Viva Las Vegas,” Merle Haggard’s “Mama Tried,” and the Righteous Brothers’ “You’ve Lost That Lovin’ Feeling.” In 1964, Campbell was called upon to replace Brian Wilson for a tour with the Beach Boys. “He fit right in,” Wilson said. “His main forte is he’s a great guitar player, but he’s even a better singer than all the rest. He could sing higher than I could!”

“I’d have to pick cotton for a year to make what I’d make in a week in L.A.,” Campbell once said. “I learned it was crucial to play right on the edge of the beat… It makes you drive the song more. You’re ahead of the beat, but you’re not.”

Campbell was married four times, and has five sons and three daughters. The singer had struggled with drug and alcohol addiction for decades. In 1981, he became a born-again Christian, and in 1982, he married Kimberly Woollen, a Radio City Rockette, who helped him clean up his life.

Campbell first revealed in 2011 that he had been diagnosed with Alzheimer’s, at 75 years old. He announced in June of that year that he’d be retiring from music as a result. His final studio album, Adiós, was released this year.