Lightsey had piano instruction from the age of five and studied piano and clarinet through high school. After service in the Army, Lightsey worked in Detroit and California in the 1960s as an accompanist to singers. He also worked with jazz musicians such as Yusef Lateef, Betty Carter, Pharoah Sanders, Bobby Hutcherson, Sonny Stitt, Chet Baker, and Kenny Burrell. From 1979 to 1983 he toured with Dexter Gordon and was a member of The Leaders in the late 1980s. During the 1980s he led several sessions of his own, including duets with pianist Harold Danko. In the 1980s and since he has worked with Jimmy Raney, Clifford Jordan, Woody Shaw, David Murray, Joe Lee Wilson, Adam Taubitz, Harold Land and Gregory Porter.
He is also an accomplished flautist and occasionally doubles on flute in live performances.