A system for selecting music includes a mobile system for processing and transmitting through a wireless link a continuous voice stream spoken by a user of the mobile system, the continuous voice stream including a music request, and a data center for processing the continuous voice stream received through the wireless link into voice music information. The electrophotographic cluster printing system includes a plurality of electrophotograhic recording apparatuses each including a photoconductor, a charger, an exposure device, a developing device, and an image quality controller for detecting a factor concerning image quality and controlling image quality of an output image on the basis of information of the detected factor. The pattern desirably has concave and convex shape formed on at least one surface of the reflective polarizing plate. The system uses the one or more bit masks to select one or more portions of the data units and perform one or more functions using the one or more portions of the data units to generate function results.