Tuning forks emanate perfect sine wave sound patterns which allow us to fine-tune musical instruments to the proper pitch. When struck, the air around the fork vibrates, sending strong impulses through the air. Due to this intense vibration, they have been adopted by healers in order to increase the amount of energy/frequency on the specific parts of the body being healed. Tuning forks can be used in energetic healing by placing the vibrations of the fork near the different chakras on the body.
So yes, the body can be tuned like an instrument to achieve optimal physical balance. (If only it could make an alto a soprano, or a flat singer on key!) In a healing, tuning forks can be struck in order to change the body's biochemistry and create a peaceful balance between the nervous system, muscle tone, and organs. The body enters a deep state of relaxation almost instantly and leaves us with a clear, centered, and harmonious mind. The body is energized, the nervous system is balanced, and the entire self feels respite from the everyday stresses placed upon it. The meditative state brought upon by tuning forks is especially useful in enhancing massage, acupressure, and dream-work.