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CTo7

Common Tone fully diminished 7ths

"CTo7 slides" by Victoria Malawey, Multimodal musicianship is licensed under CC BY-NC-SA 4.0

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Things to know about the CTo7

  • fully diminished seventh chord
  • at least one note of the CTo7 is a common tone with the chords around it
  • embellishing function (some texts call it a “EMBo7”)
  • spelling is flexible! yay!

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Example in major

common tone

other voices move by step

one voice will move by 3rd

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Example in minor

two common tones

one voice moves by step

one voice will move by 3rd

two common tones

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CTo7 in musical context

Chopin, Nocturne in A-flat, op. 32, no. 2, mm. 1–4

PT

PED

Your tasks:

  1. identify the key
  2. identify all the tonic chords and label them
  3. find the CTo7 (there’s just one)