A new study measures the physical effect of studying music on the brain. “Among expert musicians, certain areas of the cortex are up to 5% larger than in people with little or no musical training, recent research shows. In musicians who started their training in early childhood, the neural bridge that links the brain’s hemispheres, called the corpus callosum, is up to 15% larger. A professional musician’s auditory cortex — the part of the brain associated with hearing — contains 130% more gray matter than that of non-musicians.”