Thelonious Sphere Monk (/θəˈloʊniəs/, October 10, 1917 – February 17, 1982) was an American jazz pianist and composer. Monk had a unique improvisational style and made numerous contributions to the standard jazz repertoire, including “‘Round Midnight”, “Blue Monk”, “Straight, No Chaser” “Ruby, My Dear”, “In Walked Bud”, and “Well, You Needn’t”. Monk is the second most-recorded jazz composer after Duke Ellington, which is particularly remarkable as Ellington composed more than 1,000 pieces, whereas Monk wrote about 70. His compositions and improvisations feature dissonances and angular melodic twists, and are consistent with Monk’s unorthodox approach to the piano, which combined a highly percussive attack with abrupt, dramatic use of switched key releases, silences and hesitations. He was renowned for his distinctive style in suits, hats, and sunglasses. He was also noted for an idiosyncratic habit observed at times during performances: while the other musicians in the band continued playing, he would stop, stand up from the keyboard, and dance for a few moments before returning to the piano. Thelonious Monk is one of five jazz musicians to have been featured on the cover of Time, after Louis Armstrong, Dave Brubeck, and Duke Ellington and before Wynton Marsalis.

As his health declined, Monk’s last six years were spent as a guest in the Weehawken, New Jersey, home of his long-standing patron and friend, de Koenigswarter, who had also nursed Parker during his final illness. Monk did not play the piano during this time, even though one was present in his room, and he spoke to few visitors. He died of a stroke on February 17, 1982, and was buried in Ferncliff Cemetery in Hartsdale, New York. In 1993, he was awarded the Grammy Lifetime Achievement Award. In 2006 he was awarded a special Pulitzer Prize for “a body of distinguished and innovative musical composition that has had a significant and enduring impact on the evolution of jazz.” During his lifetime, his style was not universally appreciated. Poet and jazz critic Philip Larkin once dismissed Monk as “the elephant on the keyboard”. The Thelonious Monk Institute of Jazz was established in 1986 by the Monk family and Maria Fisher. Its mission is to offer public school-based jazz education programs for young people around the globe, helping students develop imaginative thinking, creativity, curiosity, a positive self-image, and a respect for their own and others’ cultural heritage. In addition to hosting an annual International Jazz Competition since 1987, the Institute also helped, through its partnership with UNESCO, designate April 30, 2012, as the first annual International Jazz Day. Thelonious Monk was inducted into the North Carolina Music Hall of Fame in 2009.