Eugene McDuff (September 17, 1926 – January 23, 2001), known professionally as “Brother” Jack McDuff or “Captain” Jack McDuff, was an American jazz organist and organ trio bandleader who was most prominent during the hard bop and soul jazz era of the 1960s, often performing with an organ trio. He is also credited with giving guitarist George Benson his first break.

Born Eugene McDuffy in Champaign, Illinois, McDuff began playing bass, appearing in Joe Farrell’s group. Encouraged by Willis Jackson in whose band he also played bass in the late 1950s, McDuff moved to the organ and began to attract the attention of Prestige while still with Jackson’s group. McDuff soon became a bandleader, leading groups featuring a young George Benson on guitar, Red Holloway on tenor saxophone and Joe Dukeson drums.

McDuff recorded many classic albums on Prestige, including his debut solo Brother Jack in 1960; The Honeydripper (1961), with tenor saxophonist Jimmy Forrest and guitarist Grant Green; Brother Jack Meets The Boss (1962), featuring Gene Ammons; Screamin’ (1962), with alto saxophonist Leo Wright and guitarist Kenny Burrell; and Brother Jack McDuff Live! (1963), featuring Holloway and Benson, which includes his biggest hit, “Rock Candy”.