Mozart did not simply take dictation

The popular Mozart composes whole works in his head, then copies them without alteration. Surviving manuscripts make a less magical and more interesting picture. Some scores are remarkably clean; other pages contain cancellations, substitutions and rewritten passages. Letters and sketches show planning at different scales. Speed and revision could coexist.

A famous letter describing effortless, simultaneous conception was published after Mozart’s death and is widely judged inauthentic. Correcting it does not diminish his ability. He began intensive musical training as a child and developed unusual command of form, memory and notation. The evidence concerns Mozart, not a formula that practice alone makes any person a prodigy. It replaces supernatural ease with highly cultivated fluency.