Thelonious Sphere Monk was a jazz pianist and composer.

Monk had a unique improvisational style and made numerous contributions to the standard jazz repertoire (including his classic works "'Round Midnight" and "Blue Monk"). He is often regarded as a founder of bebop, although his playing style evolved away from the form. His compositions and improvisations are full of dissonant harmonies and angular melodic twists, and are impossible to separate from Monk's unorthodox approach to the piano, which combined a highly percussive attack with abrupt, dramatic use of silences and hesitations.