Studying musical training and brain development

A new study is underway to investigate the effects of 5 years of musical training on the brain, starting from when children are 6 or 7 years old. The children are participating in a program that gives kids a free education in music and free instruments; they’ll be compared to kids who are matched on age, socioeconomic background, and different cognitive measures but who don’t have a musical education.

This is an interesting study, but how will researchers interpret some of the findings? Let’s say the study shows improvements in various aspects of cognitive ability and social and emotional development throughout the five years of musical education. To what would we attribute this outcome? Is it something specific to music education, or would you see it in any long-term intensive extracurricular program that teaches kids something? Maybe you’d need to add a third group of kids to the study who are enrolled in a free non-musical education program that has a similar social/communal aspect to it.