Bravo! Bravo! Bravissimo! Bravississimo!
Where was that guy 30 years ago? He's saying what I have believed (and performed by) since I became a real musician. The whole academic saddlebags we've inherited from 200 years of nay-sayers has been wrong from the beginning, and this guy just proved it beyond even the remotest shadow of doubt. And he also proved that he's very qualified to do it. I'm just thoroughly impressed, even thrilled, to hear that.
And I'm also impressed with some particular bits of knowledge he points out, such as the fact that Mozart's cadenzas never left the keys of the movement to which they belonged. Maybe he used a Neapolitan cadence or French 6th, but he didn't modulate to those keys; just visited them. Many of the cadenzas to Mozart Concertos for other instruments besides piano were written by established professors for those instruments during the romantic era, where the nature of the cadenza was more indicative of their own era, so of course one of the things they do to make it "interesting" is jump to a distantly related key. Beethoven did it in Mozart's cadenzas, so why not them? But I'd love to see people return to Mozart's way and keep the cadenzas pure in key, but improvised in spirit.
If you ask me, I think the elimination of improvisation is one of the reasons classical music died. We hear that the greatest of improvisors were Bach, Mozart, and Beethoven, and yet we never hear anyone IMPROVISE Bach, Mozart or Beethoven, much less anyone else of the period. Naturally, it takes an intimate knowledge of form, proportion and balance, with a big knack for invention. If people did that, you'd immediately distinguish between two player's versions of any piece. Classical music would live and breathe again. And it would inform modern players in modern music to make inventiveness a part of their music again.
The "composer is god" thing was always heretical to me. I freely altered composers' intentions when I thought they lost the track, or had been poorly transcribed, and sometimes completely rewrote the piano part for my accompanists, or altered my cadenzas, and sometimes even parts of the solo itself, when I thought it was imperative to do so. We forget that between composer and listener are layers of judgment by various participants in the chain: the copyist, the editor, the engraver, the performer. Lots of room for interpretation, misunderstanding, and outright error. Lots of room for correcting those errors, or for that matter, just reinventing bad writing. (not in Mozart, of course, but certainly in Glazounov or many other 2nd or 3rd tier composers)
Anyway, Professor Levin's lecture may have seemed drab or academic to some, but to me it was a sign that the academy may be waking up after a sleep that would make Rip Van Winkle seem positively wired.
Shooshie