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