11.4 Harmonizing a Melody With Seventh Chords: Tutorial

Harmonizing a Melody with Seventh Chords

Adding a 7th above the root of a chord creates a dissonance and instability that has to resolve. This activates chords and creates forward motion. The addition of seventh chords to our melody harmonizations creates more chord choices and the opportunity to incorporate more diverse sonorities. When part writing with seventh chords, we must be mindful of how we approach and resolve the chordal seventh in a seventh chord. We must also remember that some seventh chords, like dominant function seventh chords, resolve in a specific way. To review part writing with seventh chords, see chapter 10.5.

Steps to harmonizing a melody with seventh chords

1. Identify the key.
2. Write down the chords contained in the key in root position.
3. Write in the scale degrees in the soprano voice.
4. List chord possibilities under each note in the soprano.
5. Identify the melodic phrase structure/cadence points and determine harmonic rhythm.
6. Eliminate any chords that cannot be used (either from motion in the soprano, connections between chords, or from choices made in phrasing/harmonic rhythm/cadences). When part writing with seventh chords, we can allow using iii and vi, but need be very careful of when and how they are used to prolong progressions and connect chords. We will still focus primarily on Progression, Repetition, and Tonic motions between chords.
7. Look for places where you can insert a 6/4 chord

• cadential 6/4: most common 6/4 chord, so it’s a good option to look for first
  • Used only at a cadence directly before a V chord.
  • Need a soprano line that can support tonic followed dominant harmony.
  • The cad 6/4 must be metrically stronger than the V that follows.
• Passing 6/4:
  • The soprano motion can be sustained between the 3 chords, can move stepwise in contrary motion to the bass between the 3 chords, or use lower neighbor motion between the 3 chords.
  • Make sure the passing 6/4 is connecting 2 chords of the same category (like I and I6).
  • The most common passing 6/4 chords are I6/4 between V chords and V6/4 between I chords.
  • Do not use this chord at a cadence.
• Pedal 6/4:
  • The soprano motion can be sustained between the 3 chords or will use upper neighbor motion between 3 chords.
  • Pedal 6/4 chords usually connect 2 of the same chords, or chords with the same function.
  • The most common pedal 6/4 chords are I6/4 between IV chords and IV 6/4 between I chords.
  • Do not use this at a cadence.

8. Look for places to insert 7th chords.

• Seventh chords can potentially be applied to any chords built on each scale degree in the melody.
• Any 7th chords with the chordal seventh in the soprano must resolve down by step in the soprano. If the soprano does not move down by step, you cannot use that particular seventh chord. This can help you eliminate chord choices.
• V7 is the most common seventh chord of any type, and usually found at a final cadence in root position. Use it in inversion within the phrase. It is too strong to use as part of a half cadence.
• ii7/ii˚7 is the most common non-dominant seventh chord.
• Do not use IM7/i7 like a I chord. It is not a substitute for I.
• Check the approach and resolution of each 7th chord. The chordal 7th must resolve down by step in the next chord. The chordal seventh should be approached through common tone or stepwise motion with the voice before it.

9. Look for places to insert chords in first inversion to make motion smoother (exception: we want the leap from V to I at a final cadence). Remember that you cannot use a 6/4 chord unless it is one of the types of 6/4 chords (even if trying to avoid part writing errors).
10. Write in the bass voice for your chosen chord progression and check it for errors against the soprano voice.
11. Part-write the inner voices (make good choices in connecting chords melodically). Check your answers for errors.

Summary for harmonizing a melody with 7th chords

• Follow the steps outlined for harmonizing a melody using seventh chords.
• Remember that in order to use seventh chord with the chordal seventh in the soprano, the soprano must move down by step to the next note.
• Remember to approach all chordal sevenths by common tone or using stepwise motion and to resolve the chordal seventh down by step in the next chord.
• V7 is the most common type of seventh chord and should be used in root position at final cadences and in inversions within the phrase.
• ii7 is the most common type of non-dominant seventh chord.
• Dominant seventh chords and leading tone seventh chords follow specific motion from each scale degree to the next chord. Put the scale degrees in the music to help guide the resolution.

Proceed to the theory exercises for a guided example on how to harmonize a melody with seventh chords.