Good question

I read theticle you cited. My comments:

• 10 minutes of classical music might not be enough to have an impacton our brains to become smarter or have sharp minds, but what about days, weeks,  and years of having the habit to listen to certain types of music.
• There is a problem in defining the output of the imapct of of music (or certain types of it at least) on us. I might not get smarter, but what if my imagination becomes better, and I found some interesting idea, without me getting high score in an IQ test. What if my feelings becomes better, and so and so happens. When they can formulate a satisfactory schema of the possible outcomes and how to measure them, the we'll have an answer.