Born in Champaign, McDuff first learnt the bass, before switching to organ. As the organist for Willis Jackson, McDuff came to the attention of the Prestige label. He recorded a series of classic albums as a bandleader, which cemented his soul-jazz style and did much to popularise the Hammond organ. He is also credited with mentoring guitarist George Benson. McDuff later recorded for Atlantic and Blue Note, and experimented with electronic keyboards and fusion in the 1970s. He enjoyed a resurgence in the 1980s, and passed away aged 74.