Charles Parker Jr. (August 29, 1920 – March 12, 1955), nicknamed "Bird" or "Yardbird", was an American jazz saxophonist, bandleader, and composer. Parker was a highly influential soloist and leading figure in the development of bebop, a form of jazz characterized by fast tempos, virtuosic technique, and advanced harmonies. He was a virtuoso and introduced revolutionary rhythmic and harmonic ideas into jazz, including rapid passing chords, new variants of altered chords, and chord substitutions. Parker primarily played the alto saxophone. Parker was an icon for the hipster subculture and later the Beat Generation, personifying the jazz musician as an uncompromising artist and intellectual rather than just an entertainer.