Difficult stage but the magic is that he studies what he wants and believes that it will make him happy, without thinking about the economic solvency or the possibility of finding a job or not.
Many times we focus on studying something that will provide us with financial stability in the future and we end up studying things we don't even like. But that choice is as uncertain as the future itself. It may give us some financial security, but in the long or short run, life will put us where we should be, where we are happy and feel fulfilled. In some cases (they are the fewest) that happiness and fulfillment come hand in hand with the chosen profession. I hope with all my heart that this is the case with your son. May he study music and become great, may he be very happy and may it provide him with an economically stable future. It only remains for you to accompany him on his way. I wish him the best of luck in his exams and lots of good energy.