Charles Mingus Jr. was a highly influential American jazz double bassist, composer and bandleader. Mingus's compositions retained the hot and soulful feel of hard bop and drew heavily from black gospel music while sometimes drawing on elements of Third Stream, free jazz, and classical music. Yet Mingus avoided categorization, forging his own brand of music that fused tradition with unique and unexplored realms of jazz. He once cited Duke Ellington and church as his main influences. Mingus focused on collective improvisation, similar to the old New Orleans jazz parades, paying particular attention to how each band member interacted with the group as a whole. In creating his bands, Mingus looked not only at the skills of the available musicians, but also their personalities. Many musicians passed through his bands and later went on to impressive careers. He recruited talented and sometimes little-known artists, whom he utilized to assemble unconventional instrumental configurations. As a performer, Mingus was a pioneer in double bass technique, widely recognized as one of the instrument's most proficient players. Nearly as well known as his ambitious music was Mingus's often fearsome temperament, which earned him the nickname "The Angry Man of Jazz". His refusal to compromise his musical integrity led to many onstage eruptions, exhortations to musicians, and dismissals. Because of his brilliant writing for midsize ensembles, and his catering to and emphasizing the strengths of the musicians in his groups, Mingus is often considered the heir of Duke Ellington, for whom he expressed great admiration. Indeed, Dizzy Gillespie had once claimed Mingus reminded him "of a young Duke", citing their shared "organizational genius".