Milt Jackson was an American jazz vibraphonist and composer born Milton Jackson on January 1, 1923, in Detroit, Michigan. Nicknamed Bags, he was one of the most influential vibraphonists in jazz history and a founding member of the Modern Jazz Quartet, the celebrated ensemble he co-led with pianist and musical director John Lewis, bassist Percy Heath, and drummers Kenny Clarke and later Connie Kay from 1952 through the late 1990s. As a composer, Jackson's writing was rooted in the blues, producing instrumental pieces that became staples of the bebop and cool jazz repertoire. His best-known composition, Bags' Groove, is a widely performed jazz standard that epitomizes his gift for crafting memorable blues-based themes. Other notable originals include Bluesology, a cornerstone of the MJQ repertoire, and The Late, Late Blues from his 1961 duo album with John Coltrane. Milt's Tune, featured on AllSolos, is another example of his concise, blues-inflected compositional voice. Before forming the MJQ, Jackson performed in Dizzy Gillespie's sextet and big band and recorded with Thelonious Monk, Miles Davis, and Coleman Hawkins. He died on October 9, 1999, leaving a body of work that defined the role of the vibraphone in modern jazz.