Al McKibbon, 86, whose robust acoustic bass anchored some of the most advanced and memorable jazz recordings of the 1940s and 1950s, died July 29 at a hospital in Los Angeles. No cause of death was reported.

For nearly a decade, he was at the center of the heady bebop musical revolution in New York. Among the first U.S. musicians to master the complexities of Afro-Cuban music, he provided much of the rhythmic support for trumpeter Dizzy Gillespie's experiments combining Latin American music and jazz.

"I began to feel that the Cubans were as close as you could come to African culture because they still practiced the roots of our music," Mr. McKibbon wrote three years ago in an afterword to Raul A. Fernandez's book "Latin Jazz: The Perfect Combination."

He collaborated on some of the most important recordings of composer-pianist Thelonious Monk. In 1949 and 1950, he appeared on several Miles Davis and Gil Evans recordings that resulted in the celebrated "Birth of the Cool" album. In the 1950s, Mr. McKibbon was a member of pianist George Shearing's popular quintet, and after settling in Los Angeles, he performed anonymously on many television shows and theme-song recordings, as well as with an all-star musical roster that included Ray Charles, Frank Sinatra, Sarah Vaughan, Cannonball Adderley and Nat "King" Cole.

Alfred Benjamin McKibbon was born Jan. 1, 1919, in Chicago and grew up in Detroit. He began his career as a vaudeville tap dancer, switching to bass at his brother's suggestion when the string bass began to replace the tuba in jazz groups.

After working with Lucky Millinder's traveling big band at a Detroit nightclub, he joined Millinder full time during a 1944 engagement at Washington's Howard Theater. Later that year, Mr. McKibbon was in New York, sitting in at Minton's Playhouse, the Harlem club where the bebop revolution was launched by Monk, Gillespie and saxophonist Charlie Parker.

In 1945, he landed one of his most important early jobs while in the audience of a New York nightclub. When the bass player for tenor saxophonist Coleman Hawkins did not show up, Mr. McKibbon went onstage with a borrowed instrument; from then on, he never lacked work.

He was part of Norman Granz's Jazz at the Philharmonic tours in 1945 and 1946, then joined Gillespie's big band in 1947. A fellow member of the rhythm section was Cuban conga master Chano Pozo, who taught Mr. McKibbon the intricacies of Cuban rhythms.

"We basically spoke pidgin English to communicate," Mr. McKibbon told Latin Beat magazine this year, "but we understood each other primarily through our music."

Inspired by the infectious, syncopated beat, Gillespie wrote several Latin-style tunes, including "Manteca" (Cuban slang for "marijuana" at the time), which featured a solo bass introduction by Mr. McKibbon.

"We had no idea we were creating anything new other than just a union of jazz with Pozo's conga drum," Mr. McKibbon said. "We were not thinking of the moment as some new genre being invented."

While working intermittently with Gillespie from 1947 to 1950, Mr. McKibbon also appeared with jazz greats Johnny Hodges, Earl Hines and Count Basie. In 1947, he performed on "Genius of Modern Music," the landmark two-volume work that featured the compositions of the enigmatic Monk.

"Thelonious would come to my house unannounced," Mr. McKibbon told Latin Beat, "and sit at my table with a matchbox full of pot and a pint of whiskey and sit there all evening and still be there when I woke up the next morning. Sometimes he'd stay there for two or three days. I never knew why, and I never asked."

From 1951 to 1958, Mr. McKibbon was the backbone of Shearing's quintet, but he left the road to settle in Los Angeles. He joined the NBC studio orchestra and worked in other ensembles. He performed on the Dean Martin, Bob Hope and Carol Burnett shows, and played on many TV theme songs, including "Gunsmoke," "Green Acres," "Batman" and "The Odd Couple."

He continued to lead his own groups, mostly in California, until the past few months. He made his first and only recording as a bandleader when he was 80, performing the quirky tunes of Monk and the lively Latin jazz he had learned from Pozo and Gillespie more than a half-century before.