Is Wolfgang punching up, down, or sideways?
Wolfgang detests fellow-clavierists for the most part. One of them, Von Beecke, whom he constantly berates as a fool & a blockhead, wrote some perfectly lovely sonatas — discreet cough — not so very different from Mozart's own work in the 1770s. I'm utterly fascinated by the interaction, which requires looking at the whole thing from two directions: Mozart has the upper hand in so many ways, guaranteed by his (posthumous) position in the canon & the fact that, even when he is an awkward young adult, no longer a prodigy but not yet — indeed, not ever — a successful, well-paid Kapellmeister, he is for the most part engaging & perceptive. However, in the letters Mozart is really savage about von Beecke's intellect. Something I learned from my brief stint working in the tech sector, a field that overflows with touchy, capable young men, is that if they have nothing substantial by which to criticize a person, they invariably turn to two kinds of name calling: that person is incompetent, & that person is stupid. And it is usually deployed against people who have things the speaker feels entitled to. Mozart's lack of grace, in the interaction, is a clue to something he cannot access about von Beecke. The point is not to salvage von Beecke's reputation or tarnish Mozart's, it's to look at the ways that the institution of music history erases people like von Beecke (& many others: Marie Anna 'Nannerl' Mozart, Joseph Bologne de St-Georges ...) by the circular argument that the only musicians worth knowing are the musicians we already know.
Mozart may be by conventional opinion the better composer, even by my own judgment — I truly love Mozart — but it's really hard to see that when the entire genre of writing about music since the mid-C18 insists on classifying composers into a tiny number of exemplary 'garden plants' & hosts of despicable 'weeds'. Being obscure is given as proof of mediocrity. I'd love to compile & present the whole dossier on von Beecke, since a number of heavyweights judge him an excellent musician. Burney & Schubart, though they themselves were dismissed from the Valhalla of music erected in the 19th century, were both people of taste & experience, & I think they were absolutely on to something when they say they found Mozart's playing stodgier than von Beecke's. No person alive has heard Mozart play; it appears that we need to reconcile the testimony of two eyewitnesses with ... the opinion of the Mozarts themselves. An irony with a delightfully C18 flavor, don't you think?