Webster's Definition: "the property of a sound and esp. a musical tone that is determined by the frequency of the waves producing it : highness or lowness of sound"
My Definition: How high or low a piece of or aspects of a piece of music sounds.
There really doesn't seem to be anything else to know about pitch, now does there? It's the highness or lowness of a piece of music. And that's it...right? Wrong. The idea of pitch is actually a lot more complicated than just highness and lowness. It's a scientific concept based on frequency and the periodic disturbance of air particles.
So, since pitch is about the highness or lowness of sound, let's discuss the science of sound. Sound is vibration. It is created when air particles are disturbed and the disturbance travels to your ear, where it's perceived as sound. Frequency is basically how fast or slow those air particles are being disturbed. Higher pitches come from faster frequencies, and lower pitches come from slower frequencies. If you wanted to measure the frequency or pitch of a sound, you would do so in Hertz (Hz), which is a unit of measurement for sound waves.
So, again, pitch is how high or low a sound is. Which, as we just learned, is determined by the frequency of the disturbed air particles that make up sound. The easiest way to visualize pitch in a musical sense is with a piano keyboard. Each key has a different pitch.
Here you can find a great interactive way of seeing all of those different pitches on a piano keyboard.
Note: "MIDI" stands for Musical Instrument Digital Interface. It's basically just a universal program and unit for music on your computer.
