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 bridge for additional drone strings on some instruments). The free end of the dog (called the "hammer") rests on the soundboard of the hurdy-gurdy and is more or less free to vibrate. When the wheel is turned regularly and not too fast the pressure on the string (called the "trompette" on French instruments) holds the bridge in place, sounding a drone. When the crank is struck, the hammer lifts up suddenly and vibrates against the soundboard, producing a characteristic rhythmic buzz that is used as an articulation or to provide percussive effect, especially in dance pieces. On French-style instruments, the