Projector-based crowd coordination and messaging embodiments that separately, yet simultaneously, convey information to members of an audience in at least one part of a venue. The information conveyed to each audience member is different from the information conveyed to at least one other audience member based on their locations within the venue. In single-projector embodiments, an optical projector is mounted within the venue and projects an image onto the audience. In multiple-projector embodiments, an array of optical projectors are mounted within the venue, each of which projects an image onto the audience. In either case, for each of a plurality of prescribed locations in the audience, each optical projector projects light of a prescribed color and brightness onto the location, where the light from the projector, or projectors collectively, represents the information conveyed to an audience member or members in the location.