A spotlight, sometimes known as a follow spot, is a powerful stage lighting instrument which projects a bright beam of light onto a performance space. Spotlights are controlled by a spotlight operator who tracks actors around the stage. Spotlights are most commonly used in concerts, musicals and large scale presentations where highlighting a specific, mobile, individual is critical. Spotlights are sometimes located overhead on catwalks. In some theatres, they may also be located in the control booth or purposely built "spot booths" in addition to the catwalk. Spotlights may be arranged in a variety of patterns for coverage.