One of the big lessons that we’ve learned from the study of music and the brain is that musicians aren’t just people who play music—musicians’ brains structure their entire world in a different way. Musicians have better perceptual skills (for example, picking up the details in sounds), which lets them hear music differently, as well as other acoustic signals (such as speech). It’s not just sounds, either. There is also evidence that a lifetime of musical experience can positively affect other mental skills, leading to better ability to pay attention and better cognitive flexibility. The really crucial aspect of all this research, however, is that the mental benefits of musical training are not just limited to those people who would put “Musician” on their business card.
Anyone who has put in the effort to hone their musical skills seems to reap the benefits of this training. (As an aside, this may be one of the reasons that we tend to see so many musically talented people in successful positions in life, like the lawyer who just happens to play the piano, or the doctor who sometimes moonlights in a jazz ensemble).