Jimmy Rushing (1902-1972) began as a pianist, but developed quickly into an excellent big band vocalist. He became famous as the vocal sound of the Count Basie band and the Kansas City style. Today, surprising later recordings with the Dave Brubeck Quartet, and his last album with musicians such as cornettist Ray Nance and saxophonist Zoot Sims.
Sources:
Brubeck And Rushing (Columbia Legacy CK 65727)
Rushing: The You And Me That Used To Be (RCA BlueBird ND 66460)