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.
Synthetic instrument figure out what sort of instrument it might be. If all you can determine are basic category facts, like the fact that it can be categorized as a stimulus or response instrument, but not anything about what it's particularly designed to create or measure—if the measurement specificity is all hidden in software—then you likely have a true synthetic instrument. The DoD has created a standards body called the Synthetic Instrument Working Group (SIWG) whose role is to define standards for interoperability of synthetic instrument systems. The SIWG defines a synthetic instruments (SI) as: A reconfigurable system that links a series