Interpretation of Dominant IV7 chord moving to I64 -> V(7) -> I

Question

I need your help to figure out how to interpret a Dominant IV7 chord in major moving to I64, like:

I -> IV -> IVDom7 -> I64 -> V -> I

or

I -> ii6 -> IVDom7 -> I64 -> V -> I

This sounds very good to my ears, like a proper energetic classical cadence, but I didn't find anything to label the IVDom7 chord in the usual music theory suspects (Applied chords / secondary dominants, Tritone Sub, Augmented Sixths, Neapolitan, etc.).

What do you think would fit this better?

• Considering the Eb as an upward movement from the D in ii6
• Considering IVDom7 as a simple extension of IV as predominant
• Anything else?

Answer 1

Common-tone chord

Explanation

I think the "IV7" chord is best characterized as a common-tone chord, with C being the common tone. It functions near identically to a Co7 moving to CMaj, and the pitches resolve the same way, with the F standing in for the F# of the diminished chord.

In fact, if the Io7 is interpolated between the "IV7" and I64, it fits right in without altering the heard function of the "IV7".

Justification

Source

As justification for the interpretation, I would point to a similar example from Aldwell and Schachter, who in Harmony and Voice Leading (2nd ed., Harcourt Brace Jovanovich, 1989) devote a brief section to "Apparent dominant sevenths" (p. 520).

Very occassionally, a chromaticized common-tone chord appears in the guise of a dominant seventh.

Example

They given an example from Schubert's "Gute Nacht!" (Winterreise, D911) in which a seeming "II7" chord resolves to I. In fact, it moves through Io7 as suggested above.

Here is the excerpt from the Mandyczewski edition (IMSLP) of the score:

At the key change (m. 71), we have two measures of D (I) followed by a measure of, seemingly E7 (or, more specifically, II42), resolving in the next measure back to D (with a brief visit to an enharmonically spelled Do7 inbetween).

Here is a reduction:

Answer 2

This is not an answer so much as a discussion of some related ideas.

If what you really like in this is the Me-Re-Do (or Me-Mi-Re-Do in your example) sound that is contained in this progression starting from the IVdom7, there are some more common implementations of that than using the IVdom7. Having the IVdom7 go to the V chord is common in blues (and I64 is often labeled V64, so it's just an elongation of the V chord to play I64-V-I).

But outside of that, it was very common in the 30's at least, to play the melody Me-Re-Do by playing either II7b9-V-I or bVI7-V7-I. The flat 6th chord is called the neapolitan dominant chord. So in C that would be Ab7-G7-C. I would use the iim7 instead of the IV for the whole progression, and do I-iim7-bVI7-I64-V-I.

So in the example below I could get the same melody you might use in the top voice of your progression, but in this case the name of the chord you get the Eb from would be a neapolitan dominant chord.

Django Reinhardt probably overused the neapolitant dominant to get that Me-Re-Do sound (e.g. Nuages)

Anyhow, if it's specifically the sound of the IVdom7 you like, and not just the Eb moving toward C, this won't help, but I just thought I would add this as an interesting extension of the discussion.