Nathaniel D. Mann was an early-twentieth-century American composer who worked on several projects with L. Frank Baum.
Several of Mann's songs were included in the popular 1902 stage adaptation of The Wizard of Oz. Mann composed 27 instrumental pieces for Baum's Fairylogue and Radio-Plays (1908). Man also worked on some of the multiple Baum theater ventures that never made it to the stage. One was a comic opera titled King Jonah XIII (1902); another was Montezuma (1903), Baum's adaptation of a play by his friend Emerson Hough. The Song of the Sun (1905), a revision of Montezuma, similarly failed.
Apart from Baum and Oz, Mann wrote music for popular songs as well as instrumental pieces.