I am reading about the life of Mozart. To dublicate such genius in someone would demand from the modern people a contact with the nature, with the fractureless undisturbed form of experience and with its great variation of structures, rhythms, atmospheres etc. The whole nature view is an experience for which you can find a form if you pay attention to the details of that landscape. From those details you can pick structures like the one that you want to describe, structures with spirit of their own and witha great variation of possible expressions. So once you have something that you want to express, you can find the technical form for it by a nature landscape analogy. This is just technical skill of going from a phenomenom to its atmosphere, from there to it as a sensed phenomenom and from that to the technical form. And of course also the other way: from technical form to the phenomena in the reality with such a form and to their spirit: to their way of doing and reason for existing. Thus the technical cannot spoil the real spirit in things.
Of course one would also need the skill to experience life as a great panorama of music and the ability to see the natural unspoiled form of things in life from the tiny fragments that we have in our lives left of the natural and naturally beautiful.