The Mercury Theatre on the Air is a radio series of live radio dramas created and hosted by Orson Welles. The weekly hour-long show presented classic literary works performed by Welles's celebrated Mercury Theatre repertory company, with music composed or arranged by Bernard Herrmann. The series began July 11, 1938, as a sustaining program on the CBS Radio network, airing Mondays at 9 pm ET. On September 11, the show moved to Sundays at 8 pm.