A fabulous concerto whose first movement in particular is full of remarkable musical innovations, which in toto represent a dramatic and violent break from old ritornello form. The theme, heard in full in the opening, is only presented in fragments until after the cadenza (a pretty sweet dramatic device), and the movement features previously unheard-of muscular tussling between the solo instruments for prominence – notice how they vie for attention in the ritornello sections, nearly overwhelming them.
But the most extraordinary thing has to be the sheer prominence of the keyboard part – in fact, this movement contains the first keyboard solo in musical history, and represents the birth of the keyboard concerto (evidence indicates that Bach wrote the keyboard part because he’d obtained a new harpsichord in 1719, and wanted to show off on it.) You get rapid virtuoso sections (2:06, 6:20) and sparkling effects (6:42), and there are (absurdly) long episodic passages where literally the only thing holding the music together is the keyboard part (3:12).
But the main thing is the very long keyboard solo at the end of the first movement, which is a model of harmonic badassery. It starts off pretty interestingly – while usually cadenzas begin dramatically, here the other instruments fade out one by one (starting from 6:42), leaving the keyboard to take over. The solo initially takes a conventional path (7:03 – 8:40), hanging out for a while in D/A/G Major and so on, but then at 8:41 you get a pedal point in A (the dominant of D major) that sounds like it really ought to lead to the return of the orchestra – but nope. It leads into a rapidfire passage (8:56) that lapses suddenly into fantasia mode (9:04 – 9:16, featuring some thrilling diminished 7th chords). And then, yet again, suddenly, Bach introduces a pedal A (9:17), and ramps up the tension with a grating A/Bb dissonance (9:31) and a change in rhythm. The tension practically screams for a return to D Major -- except that this never happens. The A pedal instead leads at 9:42 into a deceptive cadence (B minor) via a secondary dominant (F# Major). So that A Bach was harping on never even turns into a D – it slips into A#, and then B. And then, right before the end of the solo, Bach fleetingly but unmistakably slips a deceptive V - V7/vi – vi cadence in yet again, at 9:56. And then, as the solo ends, you hear the theme fully restated for the first in the movement. Fantastic stuff.
The second movement is equally, if less starkly, interesting for a few reasons: its canonic basis, the use of the keyboard to suggest dynamic changes not indicated in the score, the scoring only for the solo instruments (keyboard, flute violin) and, again the prominence of the keyboard in a slow movement.
The third movement is yet another of Bach’s stunning combinations of fugal and ritornello form (which completes the movement toward fugality started in the 1st and 2nd movements). The solo instruments introduce the subject, with the subject constantly recurring as a ritornello, and the ripieno providing additional statements.
Perahia and ASMF, as always, deliver an inspired and fresh performance, with a really satisfying balance between all the solo instruments. (When the piano is used, I find that the keyboard part is usually a bit too loud in the first movement.)
00:00 – Allegro (Solo/Cadenza: 7:03)
10:27 – Affettuoso
15:48 – Allegro
