Question: What nationality is the performer of song Goodbye Pork Pie Hat?
Sentence (from "Charles Mingus"): A major proponent of collective improvisation, he is considered to be one of the greatest jazz musicians and composers in history, with a career spanning three decades and collaborations with other jazz legends such as Louis Armstrong, Duke Ellington, Charlie Parker, Dizzy Gillespie, Dannie Richmond, and Herbie Hancock.
Relevant evidence: No