The "Delta Lady" is Rita Coolidge, who was born in Tennessee and moved to Memphis in 1967, where she met Leon Russell. They started dating, and in 1969 Russell wrote this song about her. He was doing arrangements and playing keyboards on Joe Cocker's second album at the time, so he contributed this song, which Cocker released as the first single from the set. Russell included the song on his first solo album the following year.
This song's muse Rita Coolidge is one of the backing vocalists on the track. In her autobiography, she recalls Cocker recording the song at Russell's studio on Skyhill Drive in Los Angeles, where she served tea to the musicians and crew. She didn't know at the time that the song would become her calling card: She named that autobiography Delta Lady.
Leon Russell and Rita Coolidge joined Joe Cocker on his Mad Dogs and Englishmen tour, where she would sing "Superstar," a song written by Russell and Bonnie Bramlett. "Here she is, our own Delta Lady," Cocker would announce when introducing her, imprinting that appellation.
Russell wrote another song about Rita Coolidge, "A Song For You," which also appeared on his debut album. The couple split soon after, just as their careers started taking off. From: https://www.songfacts.com/facts/joe-cocker/delta-lady
