The Japanese tsuzumi is just one type of this instrument that is a stretched head held taut across a shell
[DOC] [TLE] knight revision of h-s - Oberlin College [PAR] Hornbostel-Sachs system, and most might readily know a fifth type, .... just about 
classifying instruments, but about understanding what they can teach ..... when 
bolstered by the MIMO revision, why might one persist with yet another revision?