As Wolfgang became fascinated with playing music, his father became fascinated with his toddler son’s fascination — and was soon instructing him with an intensity that far eclipsed his efforts with Nannerl. Not only did Leopold openly give preferred attention to Wolfgang over his daughter; he also made a career-altering decision to more or less shrug off his official duties in order to build an even more promising career for his son. This was not a quixotic adventure. Leopold’s calculated decision made reasonable financial sense in two ways: First, Wolfgang’s youth made him a potentially lucrative attraction. Second, as a male, Wolfgang had a promising, open-ended future musical career. As a woman in eighteenth-century Europe, Nannerl was severely limited in that regard.
Was Mozart less of a natural genius than we think nowadays? It appears so.