The piano is actually a percussion instrument in disguise! The sound is produced when soft hammers hit metal strings under tension. These strings vibrate and produce the sound. A piano has a wide variety of pitches and by pressing the keys lighter the hammers hit the strings less powerfully, producing a quieter sound.
Where are these instruments being played? Is anyone else nearby?
How can you tell?
How are they making their sounds?
Describe how the vibrations were produced and then travelled to the microphone.