Acoustic shell

An acoustic shell, also called a theater or band shell, is a curved, hard surfaced structure built to reflect sound out toward an audience rather than let it scatter in every direction. Built from materials chosen to absorb as little sound as possible, a shell is often designed to be moved out of the way when not needed, either rolling off on wheels or lifting up into the stage flyspace. The type is most often built for orchestras, bands and choirs, though it can support any performance that benefits from passive acoustic amplification.