From the video!
I, vi, iv, I = not weird. Plagal, but not weird
I, vi, iv, II half-diminished, I. This functions as a dominant chord because you can find the chord tones if you extend, in thirds, the V chord and borrow the b9 (le) from minor.
From not the video:
Which notes do we need to change to get from vi to the borrowed VI and from ii to the borrowed iio?
vi needs the root and fifth to be lowered, in this case A to Ab and E to Eb
ii needs the fifth to be lowered, in this case A to Ab
When pitches are raised, they tend to resolve up. When they are lowered they tend to resolve down. The borrowed VI chord in isolation (I, VI, ii, V, I) creates lowered tones that resolve up and makes the voice leading feel strange. The tenor voice becomes strong and interesting, but weak against the other voices. Adding in the iio gives some smoother voice leading.
Voice leading informs your decision making when using borrowed chords. Make sure that the chords you borrow have the same function as the diatonic progression.
Borrowing from parallel minor (let’s break harmony)
We use Le a lot, me sometimes, and Te rarely
given progression (diatonic to major): I, ii6, V7, vi, IV6, vii%7, I
Possible progressions with borrowed chords: I, ii6, V7, vi, iv6, vii%7, I
I, ii6, V7, vi, iv6, viio7, I
I, ii6, V7, VI, IV6, vii%7, I
-You can also borrow iio6, vmin7, i (this one is the most jarring and “worst”)
Remember! vi and iii chords have altered roots when borrowed from minor. For example, bVI and bIII. Without the notation of the flats, you may unintentionally claim that these are major chords built on diatonic roots. Ab major and A major are different, so you must label them as bVI and VI respectively (although VI wouldn’t function and would likely be V/ii).
If you want to alter the root, place a flat or sharp in front of the roman numeral. For example, C: ii%6/5 is D%7/F, bii%6/5 is Db%7/Fb and #ii%6/5 is D#%7/F#
Upper and lowercase roman numerals showcase the quality of third you have in the chord
Fifths are assumed perfect, but we have + for augmented and o for diminished.
C: #IV+M4/3 = Cx, E#, F#, A#
Mode mixture makes almost any chord viable. Mode mixture allows you to share chords from different modes when you’re in one of the modes. As an example, if you’re in C major, you can use chords from C minor. From a voice leading perspective, the two modes are exactly the same. Because the voice leading is the same, you can borrow chords from the parallel minor without changing the key.
Each of the modes have overlapping chords. The chords in C major are C, D-, E-, F, G, A-, Bo. The chords in C minor are C-, Do, Eb, F-, G, Ab, Bo. The two modes share G and Bo, so we have many options of chords to borrow. If we are in major, borrowed chords include C-, Do, Eb, F-, and Ab.
What tones need to be altered to use a borrowed chord?
Progression: I - vi>VI - ii>iio - V - I
In minor, what are our tendancy tones?
Progression: I - ii6 - V7 - vi - IV6 - vii%7 - I
Where can you use mode mixture?
The whole point of borrowing chords is to create smooth lines. If you want an inner voice to shine, use borrowed chords.
#### Example 3: Borrowing Chords from the Parallel Major Progression: i - iio - V7 - VI - iv6 - viio7 - i
Now that we have chromatic harmony, we need a way to label it all in shorthand (ae. roman numerals). How do we show alterations in roman numerals?
Say we’re in C minor and you see a Bb chord. You could label it as a VII, or a V/III. How do you know which one to use? What chord follows it? The V/III goes to a III. The VIII has other functions, often in the following progression.
If you have a bIII and you want to tonicize it, you would label it as a V/bIII. You use a borrowed chord from an unrelated key, you label the secondary dominant with its relation to the foriegn key.
You have to show function. A IV seventh chord naturally occurs as a IVM7. A I7 chord is a V/IV.
What raises a seventh chord?
The only 7th chord you don’t have to add altercations to are major major and minor minor 7th chords, because the case of the roman numeral controls the quality.
With the viio chord: