"Can you explain the physics of music?" That's what Enrico Fermi, a physicist who helped create the first nuclear reactor and atomic bomb, allegedly asked of Italian composer Ottorino Respighi in 1928. Respighi wrote the symphonic poem Pines of Rome, one of the debut concerts of the Seattle Symphony's fall season. Respighi and Fermi were passengers on a ship traveling between South America and Europe. Despite all that time and space, Respighi couldn't translate music into scientific concepts for one of the forefathers of quantum theory, particle physics, and statistical mechanics.
These days, if you want to understand the scientific reasoning behind why listening to live musical performance is good for your body and brain (unlike nuclear radiation), there are endless avenues of exploration. You could turn to psychoacoustics, for example, which examines the psychological and physiological effects of sound on humans. Or you could turn to cognitive musicology, which focuses on computer modeling of music and compares how language and music have parallel functions in the brain.
Respighi's inability to describe music to Fermi through words is funny because music itself has been described as our first language. Some theorists (neuroscientists, ethnomusicologists, biomusicologists, music therapists) have suggested that the urge in us to connect through making and listening to music is essential to our survival and the basis of social bonding. Neurobiology researchers Colwyn Trevarthen and Beatrice Beebe have measured the first musical conversations between mother and child, and they've shown that these dialogues help set in motion a child's sense of belonging and being attuned to a significant caregiver. Music has also been studied for its benefits in helping us to express and contain emotional states like anger or grief, to calm us, to organize us, to increase our ability to learn, and to decrease the intensity of our pain.
There is some controversy over whether familiar, beloved music is just as effective as listening to instrumental music in terms of positive effects on the brain and body. It seems to depend on a person's history, aesthetics, sensitivity to sound, and capacity to tolerate, cope with, and describe their own emotional states. In other words, if you don't like to sit and talk with intimates about intense emotions—or any emotions—listening to Beethoven may prove challenging and very irritating at first.
But from experience and from reading way too many articles and books on the subject, I promise you it is worth the cost of the challenge. For that matter, it's also worth the cost of a symphony ticket. The music-worshipping philosopher Arthur Schopenhauer described the evocative power of all the "passions and emotions that find utterance" in a Beethoven symphony: "Joy, sorrow, love, hatred, terror, hope, etc., in innumerable degrees." He advocated for listening to live performance as a better way to " apprehend them in their immediacy and purity." 
