barrel organs usually play 7 to 9 tunes, although small organs (usually the older ones) can play up to 15 tunes. Less commonly (and usually for large orchestrions) the pinning will form one continuous spiral and the barrel will be gradually moved as it rotates so that the pins remain lined up with the keys. In this case, each barrel plays only one long tune. Usage The barrel organ was the traditional instrument of organ grinders. With a few exceptions, organ grinders used one of the smaller, more portable versions of the barrel organ, containing perhaps one (or just a few) rank(s) of pipes and only 7 to 9 tunes. Use of these organs was limited by their weight. Most weighed 25 to 50 pounds but some were as heavy as 100 pounds. There were many larger versions located in churches, fairgrounds, music halls, and other large establishments such as sports arenas and theaters. The large barrel organs were often powered by very heavy weights and springs, like a more powerful version of a longcase clock. They could also be hydraulically powered, with a turbine or waterwheel arrangement giving the mechanical force to turn the barrel and pump the bellows. The last barrel organs were electrically powered, or converted to electrical power. Eventually, many large barrel organs had their barrel actions removed and were converted to play a different format of music, such as cardboard books or paper rolls. Combined barrel and manually played instruments Especially in churches, some large barrel organs were built as "barrel and finger" organs. Such instruments are furnished with a normal organ keyboard, in addition to the automatic mechanism, making it possible to play them by hand when a human organist is available. The barrels were often out of sight. At the beginning of the 20th century, large barrel organs intended for use as fairground organs or street organs were often converted, or newly built, to play music rolls or book music rather than barrels. This allows a much greater variety of melodies to be played. See also Barrel Organ Museum Haarlem (Netherlands) Calliope (music) Player piano Dance organ Fairground organ Musical clock Music box Organ grinder Pipe organ Serinette Street organ Notes References Diagram Group. Musical Instruments of the World. New York: Facts on File, 1976. Reblitz, Arthur A., Q. David Bowers. Treasures of Mechanical Music. New York: The Vestal Press, 1981. Smithsonian Institution.