This document discusses common tone diminished seventh (CTo7) chords, which connect two other chords through stepwise voice leading rather than harmonic function. Specifically, it notes that: 1) A CTo7 chord spells a diminished seventh but does not resolve like a typical diminished seventh chord. 2) When using a CTo7 to connect the same two chords, the rule is to double the fifth and have one fifth move up a whole step and one down a half step, with the third moving down a half step. 3) CTo7 chords can serve as passing chords between different chords rather than always returning to the original chords.

1. Linear Chromatic Chords
Chapter V.2

2. Let’s look at the chord on the word “Cross”

3. What notes do you see? What chord does
that make it?

4. The chord is…
 D#, F#, A, C
 That makes it a viio7 in e minor, right?
 If not, then it must be an enharmonic spelling of that chord, which could be
viio7 in
 E
 G
 Bb
 C#

5. How does the chord resolve?

6. The chord goes to a C chord
 This is not the right resolution for any enharmonic spelling.
 Now the learning can begin…

7. Harmony vs. Voice Leading
 Most chords arise harmonically.
 Tonic, Dominant, Pre-Dominant, etc.
 These are examples of harmonically-functioning chords
 Other chords arise through voice leading
 That means that the voices move however they move, and we get a chord.
 This music is conceived more horizontally than vertically. It’s contrapuntal
 The music of Palestrina is a good example. You can some chords, but he wasn’t
thinking chordally.

8. This chord moves step-wise, indicating
more voice-leading than harmony.

9. This is a linear chromatic chord: The
common tone diminished seventh.

10. Note how this is spelled, doubled, and how
it moves

11. Common Tone Diminished 7th
 Connects two other chords linearly
 These are often the same two chords (I-CTo7-I), but don’t have to be
 The CT chord spells a diminished 7th, but doesn’t resolve like one
 That’s why it gets the label CT instead of vii

12. Writing the CTo7 when going from and to
the same chords
 On the beginning and ending chords, double the 5th
 One fifth goes up by whole step
 One fifth goes down by half step
 The third goes down by half step
 The bass note stays the same
 That’s why it’s called a common tone chord

13. Doubled 5th, moving by half and whole
step. The word “of” is just switching voices

14. CT+6
 We can also make these chords Augmented 6th chords
 For the doubled 5th that goes up, make it move by a half step instead of a
whole step. This will automatically make it an Aug6 (maybe a diminished 3rd)
 Everything is the same, but we have a slightly different color

15. CT chords as passing chords
 As indicated in your chapter, these chords can also serve as passing chords.
 In this case, the chords don’t go back to their original chord
 There are not as specific part-writing rules for these because they chords
they connect can all be different.