# Piano is both a string instrument and a percussion instrument
Under a piano's lid, when a key is pressed, a hammer felt strikes a string to make the sound.
The vibration of the string is responsible for the sound, so a piano is a string instrument. The sound is also indirectly made by striking, thus piano can be counted as a percussion instrument as well.
Similar instruments including hammered dulcimer and using the _col legno_ technique on bowed string instruments like violins.
![[Piano hammer string mechanism.mp4]]
_Animation of how a piano key produces sound._
## Road signs
- [[Piano]]