Patients whose brains have been damaged by stroke may be mending when they sing. According to a study from Harvard Medical School these patients by the act of singing may also be regaining their ability to speak.
A music therapy that puts words to simple tunes for stroke patients showed remarkable results after only one session.
"Music has been used as a form of therapy for stroke patients since the discovery that damage to the brain's speech centers did not affect the ability to sing."
Speech and movement can be damaged easily by a stroke on the left side of the brain because that is where they are centered. But music is processed in much larger areas of the brain. And words in a song seem to help bridge the gap for the brain to be able to rebuild verbal ability and speech connections on the right side of the brain.
http://www.naturalnews.com/029150_brain_damage_singing.html