The American trombonist Roswell Rudd passed away in December 2017 at the age of 82. He developed since the 1960s a style of improvising, which was immediately recognisable. It was not primarily virtuoso, but with a lot of eloquence and feeling. Recordings are of his quartet from 1965, and with the Carla Bley Band from 1976.
Sources:
Roswell Rudd: Roswell Rudd (America 067 868-2)
Carla Bley: Dinner Music (WATT 6 825 815-2)