Intuition, it would seem, should be enough to dispel any doubts as to the remedial affects of music upon the soul. Since the beginning of time, even before the development of instruments, man saw himself in accordance with the Music of the Spheres, a concept that connected the world and all its 'tones' within harmonic proportion.
That notion that music can purge the body of its illnesses rises out of the Pythagorean tradition, in the fragments of Aristoxenus, and in the writings of Aristotle and Plato. However, it wasn't until the 19th and 20th centuries that the concept evolved into a scientific practice for healing, ushered in by the convergence of psychotherapy and the first and second World Wars. Patients of Veterans hospitals who were visited by performing musicians showed 'notable physical and emotion responses to music,' a phenomena that led to establishing a curriculum for the training of musicians.
Since then, many associations have emerged, and music has now become a widespread subject for clinical research, especially in the study of rehabilitation, mindfulness, and in autism spectrum disorders. The most recent inquiries into the latter support "connections between speech and singing, rhythm and motor behavior, memory for song and memory for academic material, and overall ability of preferred music to enhance mood, attention, and behavior to optimize the student’s ability to learn and interact."
According to a study published in 2006 in the UK’s Journal of Advanced Nursing, listening to music can help reduce chronic pain by up to 21% and depression by up to 25%.
An alternate approach, Sound Therapy, or Sound Healing, is the art of using objects of resonance—like sounding bowls or tuning forks—to send vibrations to the patient (including the voice). Though grounded in ancient tradition, the therapy has gained traction in the communities devoted to mind-body awareness.
Whether one plays an active or passive role in music, the growing body of evidence suggests that participating has an ameliorative influence on both mind and body, even when one's constitution is quite sound.