Hornybostel–Sachs

Hornbostel–Sachs is a western system for classifying instruments that recognizes five major categories: 1. idiophones, like gongs, where the main body of the instrument is what vibrates 2. membranophones, like drums, where a tightly stretched membrane is what vibrates 3. chordophones, like cellos, where a string strung between fixed points is what vibrates 4. aerophones, like bagpipes, where air directed by the shape of the instrument is what vibrates