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.
Bowed clavier Bowed clavier The bowed clavier (', ' or " in German) is a keyboard instrument strung with gut strings, the tone of which is produced by a steadily revolving, well rosined cylinder powered by a foot pedal, a mechanism similar to that found in the hurdy-gurdy. The " was illustrated and described by Michael Praetorius in his treatise on musical instruments "Syntagma Musicum" II, in the section "De Organograhia", published 1614-20 in Germany. It was re-invented by Joh. Hohlfeld of Berlin in 1751. This instrument and another one of his inventions, a device that recorded keyboard improvisations in real time,