The Hornbostel-Sachs system of musical instrument classification groups all instruments in which sound is produced primarily through a vibrating membrane.
Some commentators believe that instruments in this class ought instead to be regarded as chordophones.
Instruments in which the membrane vibrates as a result of friction.
With friction drums, the sound is produced rubbing, rather than striking.
Instruments in which the membrane is vibrated by an unbroken column of wind, without a chamber Instruments in which the membrane is placed in a box, tube or other container These instruments may be classified with a suffix, depending on how the membrane is attached to the body: