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.
Hurdy-gurdy intonation and sound quality, each string of a hurdy-gurdy must be wrapped with cotton or similar fibers. The cotton on melody strings tends to be quite light, while drone strings have heavier cotton. Improper cottoning results in a raspy tone, especially at higher pitches. In addition, individual strings (in particular the melody strings) often have to have their height above the wheel surface adjusted by having small pieces of paper placed between the strings and the bridge, a process called "shimming". Shimming and cottoning are connected processes since either one can affect the geometry of the instrument's strings. In some