Glen Campbell, the versatile singer and guitar player known for recording everything from country to Allen Toussaint’s “Southern Nights,” died Tuesday in Nashville. He was 81.

The clean-cut Campbell, who Rolling Stone said outsold The Beatles in 1968, revealed in 2011 he was suffering from Alzheimer’s.

He was the voice behind 21 Top 40 hits, including “Rhinestone Cowboy,” “Gentle on My Mind,” “By the Time I Get to Phoenix,” “Galveston” and “Wichita Lineman” during a career that spanned six decades.

His final No. 1 country hit was “Southern Nights,” recorded in 1977.

Campbell first heard the song while visiting Jimmy Webb, the songwriter who provided him with most of his signature hits. Toussaint’s recording was a languid, soulful tune. Campbell gave it a bouncy guitar intro and a more whimsical treatment.

The song earned him a gold record and a CMA Song of the Year nomination.

Campbell cut another Toussaint tune in 1990. “You Will Not Lose” was a duet with singer-guitarist Stever Wariner.

Campbell is also remembered in New Orleans for his reign as Bacchus during the 1974 Carnival season, when he was at the height of his fame.

According to a krewe history written by Myron Tassin, Campbell was joined in New Orleans by another former Bacchus, actor Jim Nabors, as well as the Smothers Brothers and singer-comedian Phil Harris. At the time, Campbell was the youngest person to reign as the super krewe’s celebrity monarch.

He was a popular choice for Bacchus, Tassin wrote, personable and generous with his time, greeting fans and krewe members at the post-parade Rendezvous at the Rivergate. “A national folk music hero had given to Bacchus a spirit to which it has become accustomed. This was the god, who upon hearing (float builder) Blaine Kern complain about his chapped lips, whipped out his Chapstick and offered it to the owner of the wind-ravaged kisser. Aristocratic? Never. Considerate and eager to help? The epitome of both.”

The seventh son in a sharecropping family of 12 children, Glen Travis Campbell was born April 22, 1936, in Billstown, Arkansas.

He began to play guitar as a boy and dropped out of school at 14 to live with an uncle in Wyoming who was a musician. The two played gigs together at rural bars.

But he soon moved to Los Angeles and by 1962 had become part of a backing band that recorded with the Byrds, Elvis, Merle Haggard and the Righteous Brothers.

He vaulted to fame with his often-sentimental tunes when gritter “outlaw” artists such as Willie Nelson and Waylon Jennings were on the rise.

“If I can just make a 40-year-old housewife put down her dish towel and say ‘Oh!’ – why then, man, I’ve got it made,” the told Time magazine in 1969.

He parlayed a career in music to a career in television and movies, eventually getting his own show, “The Glen Campbell Goodtime Hour,” which aired on CBS from 1969-1972.

Despite his wholesome public image, his private life was one of multiple troubled marriages that he said led to use of cocaine and alcohol.

He married his fourth wife in 1982 and announced he was a born-again Christian who gave up drinking and drugs. He pleaded guilty in 2003 to drunken driving and served a 10-day prison sentence after an arrest in Phoenix.

Campbell’s final release was in 2014. “I’m Not Gonna Miss You” was part of the soundtrack to the documentary “Glen Campbell: I’ll Be Me,” about his diagnosis with Alzheimer’s disease and his final tour.