Hurdy-gurdy strings are purely generated electronically by the keys and also in combination with the rotation of the wheel. The signals for drone strings and the snares are generated by the crank movements of the wheel. The data exchange of the musical information between the hurdy-gurdy and connected computers, samplers or synthesizers are managed via MIDI interface. Hurdy-gurdy The hurdy-gurdy is a stringed instrument that produces sound by a hand crank-turned, rosined wheel rubbing against the strings. The wheel functions much like a violin bow, and single notes played on the instrument sound similar to those of a violin. Melodies are
Hurdy-gurdy Is Made), known through a much later copy, but its authenticity is very doubtful. Another 10th-century treatise thought to have mentioned an instrument like a hurdy-gurdy is an Arabic musical compendium written by Al Zirikli. One of the earliest visual depictions of the organistrum is from the twelfth-century "Pórtico da Gloria" (Portal of Glory) on the cathedral at Santiago de Compostela, Galicia, Spain: it has a carving of two musicians playing an organistrum. Later on, the "organistrum" was made smaller to let a single player both turn the crank and work the keys. The "solo organistrum" was known from Spain