Organistrum, 9th century, (1870). A forerunner of the hurdygurdy, the organistrum was mainly a religious instrument which gave a constant sound, due to its bass string. It was played by two people, one of whom cranked the handle while the other pulled the keys. A wood engraving from The Arts of the Middle Ages and at the Period of the Renaissance, by Paul Lacroix, (London, 1870).