The distinction between composition and improvisation has always been fraught territory in the discourse surrounding jazz; some artists have argued that all music begins as improvisation, and what makes it “composition” is notating the ideas after you’ve played them. Even the classical composers who are held up as Western music’s greatest artists started out fucking around at the piano, testing ideas, rejecting them, playing something else, then settling on one melodic snippet as the best and writing it down, and gradually constructing a symphony or a concerto in that way. (And even then, classical concertos often leave room for cadenzas — flourishes at the end of a movement — that are meant to be improvised by the performer on the night.)