By looking at a sound wave, you can tell almost anything about the sound that was produced. By learning different characteristics of these waves, you will be better able to see the different relationships that different instruments make. By learning about different instruments, you will then be able to see what is similar and different about the sound that they produce. There are three categories of sound waves covering different ranges of frequency. Most of the musical instruments produce these waves.
Infrasonic waves are low-frequency longitudinal waves with frequencies below the audible range.
Earthquake waves are an example of these types of waves. Ultrasonic waves are longitudinal waves with frequencies above the audible range. Objects or air vibrate and transfer the waves at the resonant frequency. When and instrument is played, the column of air within the tube vibrates at the same frequency, or in resonance. This amplifies the sound.