Harmonic Overtones

Have you ever wondered why different instruments have completely different sounds, even when playing THE EXACT SAME NOTE?

It's mainly because of "Harmonic Overtones".

Basically, the pitch we hear comes from vibration. So if for example we use the note "A" vibrating at 440 Hz, it will ALSO vibrate at frequencies above that, at multiples of 440 Hz (eg 880 Hz, 1320 Hz,
1740 Hz).

These frequencies will have different strengths of vibration according to the type of instrument playing, so as an example, a trumpet may vibrate more strongly at 880 Hz, and a piano may vibrate more
strongly at 1320 Hz.

There are MANY frequencies vibrating simultaneously. and the strength of these vibrations determines the TIMBRE of the instrument.

This is why a piano doesn't sound like a trumpet (or an elephant for that matter)