Hurdy-gurdy twenty-three different forms, and there is still no standardized design today. The six-stringed French "vielle à roue" is the best known and most common sort. A number of regional forms developed, but outside France the instrument was considered a folk instrument and there were no schools of construction that could have determined a standard form. There are two primary body styles for contemporary instruments: guitar-bodied and lute-backed. Both forms are found in French-speaking areas, while guitar-bodied instruments are the general form elsewhere. The box form of the "simphonia" is also commonly found among players of early music and historical re-enactors.
Viola organista his notebooks of 1488–1489 and in the drawings in the Codex Atlanticus and Manuscript H. In the first model the friction of the strings was achieved by a mechanical bow traveling sideways. The second model featured a single rotating wheel, similar to that of the earlier hurdy-gurdy, to play strings. It differs in that a hurdy-gurdy has a small number of strings that are constantly in contact with the wheel, rather than a larger number of strings that can be lowered onto the wheel. A hurdy-gurdy has a keybox with tangents that change the pitches of the strings, rather like