Ferris-wheel type device (usually) which stores 2 to 12 perforated paper rolls and changes them automatically, usually in the sequence in which they are placed on the changer mechanism (or, if desired, a particular roll can be selected). Several variations occur, including a device made by Philipps which incorporates extra roll-holding sections which hang below the basic revolver mechanism; and a 10-roll cartridge-type changer unit, called a 10-roll magazine, by Popper & Co., but constructed on different principles from those used in a standard revolver- or magazine-type mechanism. Perhaps the most sophisticated roll changing device was one developed by Hupfeld, which, in its most elegant form, consisted of two 10-roll changers arranged side by side (for a total selection of 20 rolls) and equipped with a device for selecting a desired roll from a distant control panel or wallbox. In America, the Wurlitzer Automatic Roll Changer (capitalized in Wurlitzer’s usage) achieved fame, as did the Philipps-made roll changer employed in many Wurlitzer PianOrchestras. For use in a Hupfeld, Philipps, or Wurlitzer roll changer, rolls were made with a wood (Hupfeld) or metal rod in place of the normal tapered end and tab. In the Duo-Art Concertola, a separate metal rod with a hook was attached to each roll, enabling the use of rolls with ordinary end tabs. * Synonyms: magazine system, revolver system.