Young, Lester Willis (1909-1959), a tenor saxophonist, developed one of the most imitated styles in jazz history. More than any other jazz instrumentalist, Young was responsible for the transition from the "hot jazz" style in the 1930's to the more relaxed, behind-the-beat approach usually known as "cool." He did his best work while playing with the Count Basie band from 1936 to 1940. His solos on "Oh, Lady Be Good" (1936) and "Lester Leaps In" (1939) as well as his background playing for singer Billie Holiday were especially influential.