Abstract: A performance shell (1) for outdoor music performance including a platform (2) providing a performance area for receiving at least one sound source, the platform combining unitarily with a rear wall reflectors (5), side wall reflector (6) and a canopy reflector (7) to define an enclosure having a front opening (11) for communicating acoustically with an open air audience area. The canopy reflector includes a main portion (8) extending above the performance area and a projecting portion (9) projecting forwardly of a front edge of the performance area, the canopy reflector further including sound diffusion formations (13) on an underside of the main portion and the projecting portion and adapted to provide non-specular reflection of sound from the at least one sound source for enhancing sound received both in the performance area and the audience area.