Parker was a highly influential jazz soloist and a leading figure in the development of bebop, a form of jazz characterized by fast tempos, virtuosic technique and advanced harmonies. Parker was a blazingly fast virtuoso, and he introduced revolutionary harmonic ideas including rapid passing chords, new variants of altered chords, and chord substitutions. His tone ranged from clean and penetrating to sweet and somber. Parker acquired the nickname "Yardbird" early in his career on the road with Jay McShann. This, and the shortened form "Bird", continued to be used for the rest of his life, inspiring the titles of a number of Parker compositions, such as "Yardbird Suite", "Ornithology", "Bird Gets the Worm", and "Bird of Paradise". 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.