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:
Voice leading often demands that you omit a note in a chord. In any dominant seventh chord, which note is the best to omit?
a) The root?
b) The 3rd?
c) The 5th?
d) The 7th?

Check back on Friday, January 14th to see if you’re right!
ANSWER for 1/10/22
c) The Fifth. A dominant seventh chord needs its third and its seventh because these are the tendency tones, whose resolution is crucial. We also need the root, because that’s the note that defines the chord. Without the root, it becomes a diminished triad. It’s true that V7 and vii diminished are interchangeable as approaches to I, but V7 gives a more solid authentic cadence. So the only expendable note in a dominant seventh chord is the fifth, the least active tone. Without it, we still have the defining note and the tendency tones that make a dominant seventh chord really function.

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