There’s a nice piece in the NYRB about Charles Mingus and the recent box set The Jazz Workshop Concerts: 1964-5.
Mingus composed—as he did most things—his own way. He was well versed in theory and composition, yet he used notation sparingly, working out ideas at the piano and playing or singing them to his musicians, who would learn their parts by ear, a few bars at a time. He sketched out just enough to give each band member a sense of what he was meant to do, often providing pedal points or snatches of scales, or even simply suggesting moods. The reed player Yusef Lateef recalled his own experience learning Mingus music: “On one composition I had a solo and, as opposed to having chord symbols for me to improvise against, he had drawn a picture of a coffin. And that was the substance upon which I was to improvise.”
Here’s Yusef with Mingus playing over a coffin in a really terrific Mingus piece.