Concussion idiophones or clappers
Castanets
Hornbostel - Sachs
Cymbals
The substance of the instrument itself, owing to its solidity and elasticity, vibrates and radiates sound when struck. The player strikes together two or more sonorous vessels to create clearly defined individual strokes. Even a slight hollow in the surface of a board counts as a vessel.
Concussion vessels or vessel clappers
Concussion bells