The Ancient Greeks are the originators of Music Therapy. Of all the ancient peoples, they are the only ones who used it systematically to heal physical and psychological ailments.
Pythagoras discovered the mathematical rules between the frequencies of two notes. Some simple rules, e.g. like those of the notes of one octave, he considered to be "harmonic", and he was sure that similar rules apply to the entire universe (e.g. the ratios between the planetary orbits) and to the human psyche.
The universe, the human psyche and music are governed by the same harmonic principles. If the balance of opposites in the psyche is disturbed, mental illness results. Music is able to restore the harmony of the soul. Plato taught that music was not given to man to amuse his senses but to heal the vagaries of the soul and the body.
Aristotle claimed that the emotions aroused by music can relieve any type of stress.
Asclepius used music to heal neuroses.
Noted music educator Dr. Arthur W. Harvey teaches that illness is caused by discord in the vibrational state of a person.
Loud music with a quick tempo can resonate with the sympathetic system and cause overproduction of adrenaline. As a result we feel stressed or we feel our energy being drained.
On the other hand, music whose tempo is slower than the rhythm of the heart and not louder than 70 decibels has a positive impact on our health.
Uniform sound sequences with high monotony can reduce stress and aggresiveness. These physical reactions result in a deep relaxation that is a prerequisite for all types of therapy.

Many people wonder how the sound bowls from Thibet can have so powerful an effect on the body that they relax and energize it.
The answer lies in the the particular range of sounds produced by the bowls.
The basis of healing with sound and music is resonance, because the principle of acoustic resonance is true not only for musical instruments but also for the human body. When the sound waves enter the body, the living cells start to vibrate and try to restore and strengthen the state of health.
The vibrational frequencies of the the sound bowls help the brain slow down its activities. The brain goes from a Beta state to the Alpha state, or even to the Theta state which normally is associated with periods of sleep or deep meditation. When we are afraid, the brain is in the Beta state. Fear is also associated with aggressive behaviour (rapid Beta waves). The sound of the bowls help the brain go from the Beta state to Alpha. Externally, this is felt as reassurance and relief from fears and tensions.
Psychological studies have shown that fear reduces human intelligence. With sound therapy a person can relax. When we are relaxed, our own system has the chance to heal any disharmony in our organs.
Thus, through sound therapy we can be healthy, happy, intelligent and creative, and in touch with ourselves and with the Universe.