Two theater producers try to stage a wartime charity extravaganza called Cavalcade of Stars. The egotistical Eddie Cantor has Dinah Shore under contract and will only allow her to appear if he is made chairman of the benefit committee, so he is allowed to take command. Meanwhile, an aspiring singer and his songwriter girlfriend conspire to get into the charity program by replacing Cantor with their lookalike friend, tour bus driver Joe Simpson. Many of Warner Bros.' stars performed in musical numbers, including several who were not known as singers. The show features the only onscreen musical performances by Bette Davis, Errol Flynn, and Olivia de Havilland.