Many studies have proven that music programs in schools aid children in other areas of learning. A recent report on NPR about children's brains adds to the list of positive outcomes to having music in a child's life.
The late Oliver Sacks published Musicophilia: Tales of Music and the Brain [781.11 SAC, also eBook] back in 2007. The book is a fascinating look at music and all types of brains--young, old, healthy, unhealthy, etc. More on music and the brain can be found in the DVD, The Musical Brain: A Journey of Discovery into the Mystery of Music [DVD 781.11 MUS].