Because everything (including you) is about vibration and balance. Your body and all matter exist at different rates of vibration and have their own resonant frequencies. Therefore, sound and vibration play a fundamental role in your life by affecting physical, mental and spiritual levels of your human being.
The creative and transformative potential of sound has been scientifically verified. Sound vibration actually changes the structure of matter.
As you increase the frequency the matter keeps forming more complex patterns. Note that these patterns are strictly the result of physical vibration.
This action of vibration on matter is known as Cymatics. Hans Jenny (1904-1972), the father of Cymatics, claimed that physical healing could be aided by vibrational tones. Now we know that he was right. Researchers and sound therapists use specific healing frequencies to bring harmony and balance in the physical body.