Crepuscule with Nellie is a jazz ballad by Thelonious Monk, first released in 1957 on the album Monk’s Music. It was composed as a tribute to Monk’s wife Nellie during her thyroid surgery that year. The piece is renowned for Monk’s distinctive harmonic exploration and melodic approach, opening with a contemplative solo piano and gradually adding texture in some versions. It features unusual harmony such as a Gb7b5 chord and a mix of whole step and half step movements that contribute to its signature sound. Although many transcriptions place it in Bb, it is often heard in Ab major. The original recording features Monk on piano, Art Blakey on drums, Wilbur Ware on bass, with a horn section including Gigi Gryce, Coleman Hawkins, John Coltrane and Ray Copeland. Since its debut, Crepuscule with Nellie has inspired numerous interpretations by artists such as Jason Moran, Greg Lewis and Spike Wilner.