John Birks "Dizzy" Gillespie (October 21, 1917 – January 6, 1993) was an American jazz trumpeter, bandleader, composer and occasional singer. Dizzy Gillespie was a trumpet virtuoso and improviser, building on the virtuoso style of Roy Eldridge but adding layers of harmonic complexity previously unknown in jazz. His beret and horn-rimmed spectacles, his scat singing, his bent horn, pouched cheeks and his light-hearted personality were essential in popularizing bebop.