I7 goes to....VI7?

[Camille]

So, here is a I4-2 chord(or perhaps III4-2, depending on whether or not you consider there to be a modulation to relative major) that does not function as V7/IV (or V7/VI). It's not an augmented sixth chord, and it's not a deceptive cadence, so it doesn't fall into any of the "looks like a V7 but isn't" categories that I'm familiar with. I understand how the chord functions, but if there is a term for it, I don't know it:

Bach WTC Book I - Prelude VI in D minor



The odd chord is on beat two of measure 6. I understand that Bach saw inversions as being wholly different from their root position counterparts, but I don't think I've encountered this usage before in analysis (which I don't really do all that often).

[VicDiesel]

I don't think this is harmonically analyzable: the important progression is the VI7 -> ii. The progression I -> VI is just a setup for this (relative) V->I.

As my theory teacher said "You're allowed one sideways jump, and then you need to follow the circle of fifths again". The fact that this sideways jump (the I->VI) uses a dominant is interesting, but I think justified from voice leading. Bach could have used Fmaj7 (how do write that in roman numerals?) but using Eb as leading tone introduces the Gm scale.

Victor.

[Camille]

Originally Posted by VicDiesel

Fmaj7 (how do write that in roman numerals?)

I∆7 is how I would write it.

[stevel]

Originally Posted by Camille

and it's not a deceptive cadence,

Bach WTC Book I - Prelude VI in D minor

Ahh, but it is - or could be. Think about it. In the key of Bb, what is F7 to Gm? It's a deceptive cadence, isn't it?

It is not uncommon to include a "passing chord" in between a V7 and VI(vi).

For example, usually you see:
Eb - Eb - D
C - C - Bb
A - A - G
F - F# - G

Note the one chromatic note (F#) that changes the V7 of the key of Bb to the viio7 of Gm.

Now, this would only be true if it's clear we've modulated to the key of Bb. F7 of course usually implies that we are going to, but I'm not familiar enough with this one to know what happens next.

Another explanation - assuming it's staying in F Major, is that it's simply

I - ii. The Eb "comes from" the key of the ii. So you have:

I - V7/ii | ii

with the Eb in the bass simply "foreshadowing" the key the secondary dominant is pointing to (there's an actual term for this but I forget it right now).

If it were modulating to Gm, then the F could also be serving as the pivot chord as VII (I use VII for FAC in Gm, and viio for F#AC) becoming VII7 (FACEb) which is a diatonic chord in Gm which frequently leads to the dominant (as does A-C-Eb - iio in Gm - assuming the F note has some NCT function).

So there are a lot of possibilities here depending on where it's coming from and where it's going to. Basically, the chord with the F# is either "simply" a passing harmony, or, it is playing a functional role as a Dominant to the key of Gm (or possibly tonicizing ii in F, or even vi in Bb major).

I have my WTC around here, and I'll try and dig it out, but I'll be busy the next couple of days.

HTH,
Steve

[stevel]

Originally Posted by Camille

I∆7 is how I would write it.

The "triangle" or "delta" is commonly used in jazz or "pop" chord symbols. Most academic texts with which I'm familiar typically do this:

I^M7 for Major 7 chords (so like I^M7 and IV^M7)
V⁷ Dominant 7 chords (V⁷, IV⁷ in minor, and VII⁷ or bVII⁷)
ii⁷ for minor 7 (ii⁷, vi⁷, etc.).

Best,
Steve

[Camille]

Yeah, I know how they do it. I still use the delta symbol, though, and none of my profs complain. I've even seen the written-out version more often in jazz - I just don't like it cause it takes up too much space.

[stevel]

Originally Posted by Camille

Yeah, I know how they do it. I still use the delta symbol, though, and none of my profs complain. I've even seen the written-out version more often in jazz - I just don't like it cause it takes up too much space.

Yes, I've seen the "Maj" ones too.

Personally, I like the consistency of:
M or m, or +, or o.

I don't really like "-" for minor because it's too easily mistaken for a stray mark on the page (especially on photo copies).

So we should do all symbols:

^ (that's my delta), - , +, o

or all letters:
M, m, A, d

Of course the problem with the letters is that A and D can be mistaken for pitch names.

Most university texts I use use the M, m, +, o, so I go with that :-)

What about the analysis though???

Steve