SAN PABLO, CALIF. - Jimmy McCracklin, a popular blues singer and pianist whose career spanned more than six decades and whose songs were recorded by such performers as Otis Redding, Joe Tex, Elvin Bishop and Jerry Garcia, died Thursday at a nursing facility in San Pablo, Calif. He was 91. He had diabetes and hypertension.

An entry in the Encyclopedia of the Blues, published by the University of Arkansas Press, calls McCracklin "one of the great composers in blues history, with his depth of feeling, his sense of phrasing and his conciseness."

McCracklin had a rare ability among blues singers to adapt to changing musical tastes. While his earliest records from 1945 were sung to a lone piano accompaniment, his later records encompassed jump blues, rock-and-roll and soul music.

His most popular track, "The Walk" (1958), a jaunty dance song propelled by guitarist Lafayette Thomas' syncopated guitar hook, reached No. 7 on the Billboard pop charts.

The song garnered McCracklin an appearance on "American Bandstand" and charted again in 1980 in an almost note-for-note remake by the Inmates, a British band.

Through the 1960s, McCracklin had a string of self-composed rhythm-and-blues hits that bridged the gap between blues and the newer Southern soul style. The songs included "Just Got To Know" (1962), "Every Night, Every Day" (1965), "My Answer" (1966) and "Think" (1965), which was later recorded by Garcia, of Grateful Dead fame.

McCracklin also was remembered for a song that he cowrote but didn't originally record, Lowell Fulson's "Tramp" (1967), a standard among soul performers. It was covered that same year by Redding and Carla Thomas, who did it as a duet, and by Tex, who retitled it "Papa Was, Too." The song proved to have a long shelf-life: In 1987, the duo Salt-N-Pepa redid it in a hip-hop style.

The half-spoken song, at times almost a proto-rap, was a humorous expression of pride for rural African-Americans, many of whom had recently relocated to the city.

In later decades, McCracklin became a mainstay of blues festivals and was regarded as something of a blues elder. The Los Angeles-based roots-rock band the Blasters took their name from McCracklin's backup unit, the Blues Blasters.

James David Walker was born on Aug. 13, 1921, in Helena, Ark., and took the surname McCracklin from his stepfather. When he was 9, his family moved to St. Louis, where he met Walter Davis, a popular blues singer and pianist of the 1930s who taught the youngster the basics of blues piano.

He made his first records in Los Angeles in 1945 and then moved to Richmond, Calif., near Oakland, in 1947.

In a 2003 interview with writer Lee Hildebrand in Living Blues, McCracklin reflected on his approach as a blues writer and the lessons learned from Davis. "He [Davis] said, 'What I write, I put the truth in there because I want to tell you about what happened to me could happen to you or what happened to you could happen to me,' " McCracklin said.

"This is the way I put my lyrics together," he added. "It's real life."