Monk, Thelonius(Thelonius Sphere Monk), 1917–82, American jazz pianist, composer, and arranger, b. Rocky Mount, N.C. Monk is considered one of the most important, and eccentric, figures in modern jazz. He spent most of his life in New York City, playing in nightclubs; in the 1940s he was one of the first players of bop. His style was astringent, marked by discordant harmonies, alternating rhythms, and melodic interpretations. There was a subtle mixture of cynicism, humor, and warmth in his interpretations. Among the many jazz pieces Monk composed, the best known is probably "Round Midnight." Others that have become standards include "Monk's Mood," "Straight No Chaser," "Crepuscule with Nellie," and "Epistrophy."
See biographies by L. Gourse (1997) and R. G. G. Kelley (2009); study ed. by R. Van Der Bliek (2001); C. Zwerin, dir., Thelonious Monk: Straight No Chaser (documentary film, 1989).