Key points are not available for this paper at this time.
Erich M. von Hornbostel, Curt Sachs, Classification of Musical Instruments: Translated from the Original German by Anthony Baines and Klaus P. Wachsmann, The Galpin Society Journal, Vol. 14 (Mar., 1961), pp. 3-29
Hornbostel et al. (Wed,) studied this question.