Show off your theory chops with my weekly challenge! You’ll find a new question here every Monday. Please comment to post your reply.
This week’s challenge:
In last week’s challenge we said hello to this Phrygian cadence in Bach’s Toccata and Fugue in D minor. This week, what type of chord would you get if you sharped the root of the iv6 chord? Careful: make the root sharp, not the bass:
ANSWER for 6/21/21
Those of you who crossed the Alps for an Italian holiday: CORRECT! By sharping the root of the iv6 chord in a Phrygian cadence, you end up with an Italian augmented sixth chord. And this is very likely the origin of the Italian 6th: a chromatically embellished Phrygian cadence. Listen to both:
This B-flat Italian 6th is enharmonic with a B-flat dominant seventh chord, but the sharped root is spelled G-sharp, not A-flat. And spelling makes all the difference. When you hear how this chord resolves (the augmented 6th goes outward to the octave), that’s when you can distinguish it from a Bb7.
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An Italian Augmented 6th chord with a nonstandard doubling of scale degree 6 (Bb) rather than the usual doubling of scale degree 1 (D).
You would get the secondary leading tone chord of the dominant.
Hi Johnny, thanks for chiming in! It does contain two of the notes in the secondary leading tone chord of V, but you’d have to also have a B natural, and we have B flat!
Super job, Doug! And doubly correct with your note on doubling; it’s usually the third of an Italian 6th that’s doubled.
B-flat, D, G# is Italian 6th. So it’s an inverted It6 resolving back to D Minor. I think? Lol.
Correct and well done MT! However, this Italian 6th is in root position, resolving to the V chord (A major).
Italian 6th
Right you are, Charles! Ciao!
You get the major of what was a minor.
In the key of d minor, iv6 is Bb-d-g.
Sharp the root: Bb d Ab, which I would call Bb7
Hey Michael! You’ve got all the right pitches, but, since we’re sharping the root, we have to keep the original letter name. So it’s G sharp, rather than A flat. And we end up with a chord that’s enharmonic with a Bb7, but it actually has a very different name.