Analysis by Key: Another Look at Modulation

CARL SCHACHTER
My derivation of the aria's complex tonality from an underlying BW diatony
illustrates the difference between Schenker's approach and other monotonal
theories, notably Schoenberg's. Schenker's notion of Auskomponierung allows
him to find meaningful larger contexts for chords (including tonicized chords)
that are not under the control of an immediately perceptible local tonic. He can
do this because he recognizes counterpoint as a shaping force in composition, a
force that can give rise to successions of chords and, indeed, to 'keys'. Giving
counterpoint its due also allows Schenker to recognize the vastly different roles
that the same 'region' can play in different contexts: e.g., bVII in what is
essentially a tonic prolongation at the beginning of Beethoven's Op.53 and the
AS major as part of an unfolded V in 'Voi che sapete'.
I hope that I have shown convincingly that Mozart's return to Bb is not the
intentionally (though subtly) botched process that Schoenberg seems to have
thought it was. That return is not really from AW, as Schoenberg suggests; the
Ab is part of a larger F harmony (V) which sheds its tonic stability without
ceasing to direct the progression of chords and 'keys'. The prolongation of V
goes through three phases: tonicizing F (bs 21-36), unfolding it in minor form
(whence the Ab) before leading it to G (bs 37-52), and bringing the G up to A
counterpointed below by the return to an F that is now unequivocally a
dominant (bs 53-61).
Schenker's approach can lead to an understanding of how the seemingly
unrelated 'keys' of the aria's B section form an integrated whole; in this regard it
is much more successful, I think, even than Schoenberg's Theory of Regions, to
say nothing of analytic methods that simply produce a string of keys. At the
same time one must remember that the integrative powers of the arpeggiated F
chord and of the linear progression F - G - A - BS assert themselves against a
strong centrifugal counterforce that sets up quasi-independent key centres at
later levels. To concentrate on background continuity to the exclusion of
foreground disruptions is to produce a skewed picture of a piece or passage.
Example 16 shows a possible middleground structure very similar to the B
section of 'Voi che sapete' but with almost none of its richly chromatic
elaboration. Despite the underlying similarity, how different it is!
Ex. 16
! ffiWS_
9W1 r r >>
S h -- 5 - 6 6
(unfolded) °s
V 7
314 MUSIC ANALYSIS 6:3, 1987