The relationship of music to the right and left hemispheres of the brain has been studied extensively. The composer Ravel suffered brain damage in a car accident in 1933. I learned about it by reading this.
After his accident, Ravel developed Wernicke's aphasia, which gradually eroded his ability to write music. Still, he retained the ability to recognize notes and rhythmical patterns, choose his scores, even perceive that his doctor's piano had gone out of tune due to the damp winter weather. As he was to report near the end of his life, the music was trapped in his head. He could not translate his auditory imagery of a
piece of music into a visual form (by notating it) or into a motor form (by
playing by heart…Ravel commented poignantly, "I will never write my Jeanne d'Arc;
this opera is here, in my head, I hear it, but I will never write it. It's over,
I can no longer write my music." Ravel died in 1937 from complications of brain surgery.