17a Lesson - An introduction to mode mixture

Class discussion

Mode Mixture

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?

• the 3rd and the 6th
  • the 3rd and 6th are the tones that are lowered when we use chords from the parallel minor.

Example 1: Borrowing Chords from the Parallel Minor

Progression: I - vi>VI - ii>iio - V - I

• you can borrow the VI or iio in this example

In minor, what are our tendancy tones?

• le wants to resolve down
  • if you resolve le up you’ve created an augmented 2nd in a moving line

Example 2: More Borrowing Chords

Progression: I - ii6 - V7 - vi - IV6 - vii%7 - I

Where can you use mode mixture?

1. ii6 can be iio6
2. vi can be VI
3. IV6 can be iv6
4. vii%7 can be viio7
   • this is the most common borrowed chord
5. I or V can be altered if you’re feeling adventurous.
   • more likely used in minor to have a picardy third on the last tonic (major I).
   • establish your key before you alter it
   • make sure you are actually building the chord from the parallel minor
     • in C major, you would borrow Ab from C minor, not A.
     • accidentals matter
     • Batman movies love to use a bVI (like Ab).

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

• borrowing from the parallel major is much more difficult than borrowing from the parallel minor
• you’re borrowing and it’s a deceptive resolution
• iv makes it sound like you’ve modulated, and the viio creates bad voice leading
• the picardy third is the only commonly used borrowed chord from major
• a picardy third is a major I chord in a minor key

Function

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?

• Altered root: accidental in front of the roman numeral
  • a sharp raises, a flat lowers
  • do not use a natural sign Everything is altered by the root. If you have a vi and you change it to bVI from the parallel minor, the 5th is also lowered to create the correct quality of the major triad. If you want to change the fifth, you need to use a superscript symbol.
• Altered third: the quality of the third is indicated by the case of the roman numeral (ae. uppercase and lowercase)
• Altered fifth: you can alter the fifth using superscript symbols (ae. +, o, %)

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.

• Example: I - bVII - bVI - V. In this progression, the bVII does not function as a secondary dominant, it’s a passing chord. Function determines how we label chords.

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?

• an M, ex: IVM7 What lowers a seventh chord?
• a o, ex: iio7, or ii%7

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.

• Ex: ii7, V7

With the viio chord:

• in C minor, the viio is a Bdim chord, but the naturally occuring chord is Bb major.
  • we don’t indicate Bdim with a sharp in front of the roman numeral because it is so common
  • it’s a shorthand because Bb major doesn’t function in minor harmony