This is a deep philosophical question that we’re not going to get deep into. But we can at least experience it with a wave form generator and a speaker. At really low frequencies, you hear just a vague click-click-click. But as the frequency goes up, at a certain moment, it turns into a musical tone. This is the point at which our brains start to perceive the noise as a single object and not a set of discrete clicks.

When you listen to a musical instrument playing a single note, you are listening to a very complex sound wave that is repeating itself over and over again. The frequency at which that wave repeats is the frequency, and that frequency is related to the musical concept of pitch. The pitch is essentially the musical note that the instrument is playing.

Timbre is the unique sound that an instrument makes that makes it different from other instruments. For example, a horn and a piano can play the same note, but they will still sound different. Timbre is related to the exact shape of the waveform being created.

Returning to the wave form generator, the different waveforms all sound like just a click at low frequencies, and it’s not until it turns into a tone that we can really start to hear the differences between them.