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:
A whole-tone scale is just that: only whole steps, not a half step to be seen. Why does the use of this scale undermine common-practice harmony and tonality?

Post your reply and come back Friday, March 25th for the answer!
ANSWER for 3/7/22
Great comments on this week’s challenge! Common-practice harmony is centered around major-minor tonality. A whole tone scale undermines this because there are no perfect fifths, and so it’s impossible to create major or minor triads with this scale. Only augmented triads can be formed. Also, as Steve, Madison, and Brian said, with no half-steps, there can be nothing resembling tendency tones, the building blocks of common-practice cadences. Patricia and Robert correctly pointed out that there’s no sense of resolution, and that each chord sounds as much like a tonic as any other.
Because of this scale’s intervallic symmetry (based only on the whole step), it has been called a mode of limited transposition by French composer Olivier Messiaen. It can only be transposed once before repeating the same pitches, and so there are only two whole-tone scales. In the late 19th-Century, along with octatonic scales and a renewed interest in the old church modes, the whole tone scale was one of many tools that circumvented, and ultimately undermined, the rules of the common-practice.

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