“Within a few years Thompson was to become one of the most trusted people in Sun Ra’s entourage, and, some even said, the heir apparent to the leader,” the music historian John Szwed wrote in “Space Is the Place: The Lives and Times of Sun Ra” (1997).

Mr. Thompson’s devotion to the group’s music — and its theatrically attired, cosmo-futurist performance ethic — sprang eternal. At one concert, Mr. Szwed related, Mr. Thompson was locked in a three-saxophone melee of free improvisation when two of the keys became dislodged from his baritone saxophone and shot off into the audience. He used his fingers to plug the open holes and kept playing, aggressively. All of a sudden his hand got stuck in the horn, and even after the other saxophonists had grown tired and dropped out, he kept going, not knowing what else to do.

“You need to be creative like that,” Mr. Allen remembered Sun Ra telling him approvingly afterward. “He was so creative he tore the keys off; he was like that little Dutch boy and the dike!”

Danny Ray Thompson was born on Oct. 1, 1947, in New York City, to Elgie and Oscar Leonard Thompson. When he was a child his family moved to Los Angeles, where he picked up the nickname Pico, for the boulevard near where he lived. His father, a research scientist, was the first black person to receive a degree from the University of Texas. His mother, an interior designer, encouraged Danny’s interest in both music and acting.

He is survived by a half sister, Dawne Thompson; a son, Darrell Thompson; and two stepchildren, Loren and Gay Ojugbana, whom he had helped raise, and with whom he remained close after his marriage to their mother, Marilyn Ojugbana, ended in divorce.