[Smt-talk] cadential 6/4 chords

[Richard Cohn]

Yet another intervener, here to endorse Dimitar's position on the hybrid 
status of cadential 6/4 chords. My own experience of 6/4 chords that 
arrive in cadential positions (near end of phrase, fifth degree in bass, 
strong metric position) is that, under most circumstances, the arrival 
carries with it a first-default expectation of resolution to a dominant, 
with the generic down-by-step voice-leading, etc. When that first 
default is executed, I think there are good reasons to consider the 6/4 
as a dominant chord with displaced voices; and those reasons have been 
amply articulated in this discussion.

But there are times that my default expectations are not fulfilled. I 
come to find out that this "dominant" chord does things that only a 
tonic can do: for example, it can support thematic material that has 
been previously securely in the key of the tonic, and is untransposed 
from its previous presentations. To the extent that I rely on such 
associations, I hear that thematic presentation as being IN THE TONIC, 
and hence hear the chord that supports the thematic material in the 
tonic as being a tonic chord, even though it is in 6/4 position. When 
Beethoven begins the recapitulation of the first movement of the 
Appassionata or of the 4th Symphony, or when Schubert brings in the 
counter-statement of the first theme of his Bb-major Sonata, over a bass 
5^ that has been approached as if it were a 6/4 preparing a dominant 
arrival, then we are being shown how what we initially took as bearing 
dominant function is revealed to do things that only a tonic can do; put 
differently, is revealed to "function like a tonic." (Brahms was a 
master of this, as Peter Smith has shown in more than one publication.)

The origin is perhaps the classical cadenza, which is characteristically 
approached through what Vasili Byros identifies as a le-so-fi-sol bass 
scheme, culminating in a 6/4 chord that is adorned with a fermata. Here, 
if we are appropriately acculturated, we have full awareness of two 
things. Our global knowledge of the classical style makes us aware that 
the fermata chord is approached in just the way that a pre-dominant 
cadential 6/4 characteristically is ---- from an applied chord whose 
proper resolution is the dominant--- and that the fermata chord, to the 
extent that it fulfills the expectation of its application (as V or vii 
of dominant, not of tonic), bears DOMINANT function. At the same time, 
our somewhat more specific knowledge of the conventions of the classical 
concerto make us expect that the soloist will begin improvising on 
thematic material in the TONIC--- and that the fermata chord therefore 
bears TONIC function.

To claim that such a chord is nothing but tonic, or nothing but 
dominant, and walk away with arms folded, is to deny oneself access to 
the richness of this dialectic.

Many will recognize the extent to which I stand on the shoulders here of 
David Lewin's "Music Theory, Phenomenology, and Modes of Perception," 
which is my perpetual reference point for thinking about music-theoretic 
problems that otherwise might take the form of a forced choice between 
non-overlapping categories.

--Rick Cohn