A sound wave has a physical volume that can be greater in pitch or longer in duration. The physical means to change pitch and duration varies with each instrument. We may produce a wave with a vibration through a mouthpiece, vocal chords, or by striking a drum or piano key. Then, our wave must vibrate through an instrument's body, our throat, down a piano string, or into a percussive instrument.
A sound wave begins with a Pitch. It can raise or lower when our sound wave's volume compresses or decompresses, to fit dimensions of a string, drum, horn, or throat. If these instruments are shorter or thinner, the wave raises in pitch. Similarly, if they lengthen and/or widen, the pitch is lower. The wave has either more or less space/distance to reverberate.
Whether high or low pitches, a sound wave's vibration resonates within the physical material it travels along. This vibration can be across a surface, or into a column of air. We practice to exactly divide the shortness or length of our instrument, to sound the expected pitch.
"...we learn to control any physical dimensions a wave travels along."
The pitch of a sound wave has a time length, or Duration that we may control to create rhythm. A sound wave begins its path until it we stop it. We train our mouth and fingers when to activate or deactivate, at the precise moment.
Fingers activate more than one key, vocal chords begin or end despite their current position, and percussionists strike different drums, in order. Likewise, brass players' fingers and lips are caught in action to lengthen or shorten a note's duration. This mostly happens in quick succession!
Beginning musicians may compress/decompress their sound waves too much or too little, resulting in sounds that are too high or low (sharp or flat). Listening for notes' relation to one another locates a correct tone. And different instruments play in tune together when their sound waves harmonize.
Therefore, it's useful to understand a sound wave, so we may use its pitch and duration as a brush stroke. Our artistry will improve the more we learn to control any physical dimensions a wave travels along.
Basically, sound waves emerge through vibration and depth. Although we can't see a sound wave, we can hear and feel it. Higher tones are more noticeable, and lower tones vibrate whatever they hit.
Each wave's time duration may be the same, but the energy to maintain them varies. Lower waves are less compressed and need more energy to keep their duration active. So, we must blow/breathe harder to support a lower note's pitch, throughout its duration.
Finally, the amplitude, or Loudness of a sound wave takes energy. Lower waves need more energy to increase loudness, and test the limits of the material it travels through. Consequently, there's difficulty to keep a note's pitch (and duration) constant amidst an increase in force.
In summary, sound vibrations' pitch, duration, and loudness are what we control to make music. A simple idea, but these elements can become complex!
Recommended reading: Page 9