A co-founder of the band when it formed in 1969, he was central to the group's greatest commercial success in the mid-1970s, and was the writer and vocalist on the Allmans' hit single "Ramblin' Man".

By the age of sixteen Betts was feeling the need for something "a little faster", and played in a series of rock bands on the Florida circuit, up the East Coast and into the Midwest.

[3] In 1969, Duane Allman, a veteran of the South's "Chitlin' Circuit" of roadhouses and small local venues who'd gone on to form several bands with recording contracts, was casting for talent to build another around.

A successful session player, he'd gained a deal with Southern soul impresario Phil Walden, who planned to back a power trio featuring Allman.

"[4] In the initial lineup of the Allman Brothers Band, Betts was noted for collaboration with Duane Allman,[5] the twosome introducing melodic twin guitar harmony and counterpoint, which according to Guitar World "rewrote the rules for how two rock guitarists can work together, completely scrapping the traditional rhythm / lead roles to stand toe to toe".

[6] The co-lead guitars of Allman and Betts feature prominently on the band's highly regarded live double album At Fillmore East.

Betts gained additional renown for his instrumental, "In Memory of Elizabeth Reed", from the band's second album, Idlewild South, followed by his striking guitar duet-driven "Blue Sky" on Eat a Peach.

Betts's first solo album, Highway Call, was released in 1974 and featured fiddle player Vassar Clements.

[11] The Allman Brothers Band reformed in 1979 and released the album Enlightened Rogues, with two members of Great Southern replacing Allman Brothers members who chose not to participate in the reunion: guitar player Dan Toler for pianist Chuck Leavell, and bassist David Goldflies for bassist Lamar Williams.

[13] Betts returned to his solo career performing live at smaller venues, and released the album Pattern Disruptive in 1989.

Betts was replaced on numerous Allman Brothers tour dates throughout the mid-to-late 1990s, for what were reported in the media as "personal reasons".

[22][23] Betts was a Florida native, born in West Palm Beach; though he resided briefly in Georgia during the formative years of the Allman Brothers Band, he lived in the Sarasota metropolitan area for most of his life.

"[29] Betts died of cancer and chronic obstructive pulmonary disease at his home in Osprey, Florida, on April 18, 2024, at the age of 80.