Ethan Hein on Mozart "is mostly not to my taste" but as Kyle Gann put it, among we who write and play "classical music" there are more who think Mozart overrated than gets conceded in, I guess, undergrad music courses.

http://www.ethanhein.com/wp/2020/remixing-mozarts-piano-concerto-no-21-andante/

Mozart is mostly not to my taste, but there is no denying that the man could write a melody.
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To Western people, chord roots and key centers that are adjacent on the circle of fifths feel related to each other. Stepping sequentially around the circle in either direction is a good way to make your music seem logical and orderly. Another good idea is to move from relative major to relative minor or vice versa, or to move between parallel major and minor. Mozart does all of these things. If you want your music to be jagged and disorienting, then make sure not to do these kinds of key center movements.
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I use modern chord symbols because I understand them better than Roman numerals, and because several of these chords could be interpreted as functioning in multiple different ways. For example, some of the diminished chords function unambiguously as dominants (rootless 7b9 chords in jazz terms), but others are totally up in the air. Classical theorists particularly dislike it when you describe augmented sixth chords as their enharmonic dominant sevenths, but that’s what they sound like, and they make more sense to my jazz-playing brain that way.
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I can’t bring up Amadeus without referencing the iconic “too many notes” scene.

We’re supposed to understand the Emperor as being an ignorant philistine here, but he had a point. Mozart’s music is beautiful, but it can be a lot, and I would rather hear the best parts get repeated rather than hearing lots of tweedly elaborations. ...


Ableton Live turns me into a mini-Emperor, able to cut the notes I deem to be “too many” at my whim. Listening to Mozart is fine, but I’m only willing to really engage with him if I can participate actively. It isn’t just about imposing my own taste on the music. It’s about engaging Mozart in an active creative conversation, about finding the new possibilities in his music, and not just in the abstract notes on the page, but in the actual audio of an actual performance. While making my remixes, I listened to the Andante more repeatedly and more closely, than I ever would have otherwise.
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Over the years I have found that we musicians who regard Mozart as good but overrated eventually come across each other in person or, more often in our age, online.  Take this.

https://www.artsjournal.com/postclassic/2003/09/more_classical_heresies.html
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– Mozart is overrated. Actually, despite the scorn Woody Allen heaps on the idea in Manhattan, this is a less rare opinion than is often admitted. Quite a few composers I know think that Mozart’s perfection is greatly overstated. That’s not to deny that there are quite a number of perfect pieces, like the late piano concerti. But so many passages in his music (as Charles Rosen mentions) can be transferred from one piece to another with no change in meaning, like interchangeable musical bricks, a shortcoming that modern composers don’t easily forgive. In my sonata class I analyze Haydn, Mozart, and Beethoven alongside tremendously underrated composers like Clementi, Dussek, and Hummel, and side by side, Mozart’s hastily-composed piano sonatas don’t always fare well next to the lyric perfection of late Clementi or the daring innovations of Dussek.
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which reminds me that Gann also wrote that Schoenberg is overrated, too.  Hilary Hahn has gotten me to appreciate Schoenberg's violin concerto and even to put up with Mozart but that's because she's Hilary Hahn and even saying that what I love more in her discography is that she recorded Stravinsky, Bach (of course) and Ives.  I keep coming back to Bach and Ives, even more than Stravinsky (which is not saying I don't admire Stravinsky's work).

Studying Clementi has been helpful to me as a guitarist composer.  In the last twenty years I've been playing with the idea that if I study monothematic sonata forms from the likes of Haydn and Clementi that can give me a thread for how to more thoroughly incorporate blues, jazz, ragtime, rock and country elements into my guitar writing.  Mozart's music may have been perfect but it was perfect for the eighteenth century rather than perfect for helping me think through how to tackle twenty-first century musical problems regarding form, vocabulary, and gestural development.  For those problems I get more benefit studying Haydn, Clementi, Lizst (not that I LIKE him but I respect his innovations), Hindemith, Stravinsky, Shostakovich, Ellington, Joplin, Lamb, Villa-Lobos, Messiaen, even Durufle (translating plainchant into a post-Impressionist sound takes a lot of work).  Of course there's also George Rochberg, whose work I half like and half simply respect.  Mozart?  I'm reminded of a non-ironic claim that Chris Delaurenti wrote years ago about how Mozart died just when he was finally getting around to writing good stuff like his last three symphonies and his requiem. 

But Haydn, Haydn was amazing!

The observation Gann mentioned about how so many passages in Mozart could be transferred from one work to another reminds me of Adorno's scathing remark about light music and music that isn't "serious music", that in addition to being schematic in terms of tonal organization light music can have as its vice that passages can be exchanged across pieces without the basic structure of the piece being compromised or significantly modified.  I am not so sure Adorno would have gone so far as to say Mozart was light and un-serious music but he noted that Richard Wagner went so far as to say you could hear the clatter of dishes in passages of Mozart. 

I have a side bar comment I can't resist making since this is my blog, in terms of guitarist composers from the early nineteenth century I'd venture to say that the post-1800 Romantic aesthetic wasn't kind to guitarist composers.  I don't mean to suggest Sor and Giuliani got ignored within the guitar scene, they became the pillars of the guitar literature but perhaps in terms of the sheer size and seriousness of Sor's works and the Mozartean virtuosity of Giuliani their works managed to fit an essentially Romantic conception of what sonatas ought to sound like on the guitar.  By contrast Matiegka and Molitor can seem lightweight, although frankly I think Matiegka's approach to sonata forms is far more inventive and interesting than Sor's even if Sor has more memorable tunes.  What I'm starting to think as I study Robert O Gjerdingen and other scholars on earlier pre-Romantic music is that we guitarists have found Matiegka wanting as a Romantic era composer when it might be more fair to Matiegka's legacy to regard him as a late-late galant composer.  If Schubert made a point of adding a cello part to Matiegka's trio and publishing it as a quartet does that mean Schubert "elevated" the Matiegka trio or could it be a signal to us in the twenty-first century that within Matiegka's own lifetime his works for guitar may have been more highly regarded by guitarists (Schubert did play) than subsequent nineteenth century myth-making allowed for.

Which reminds me that I want to get around to blogging through more of Matiegka's guitar sonatas but that has to wait.  I've got other things going on.