Jazz Theory 15
for Improvisation

  1. Combining Chords and Modes
  2. Chord Function
  3. Most common Scales for Improvisation
  4. Scale for the Diminished 7th Chord
  5. Quiz - Quiz Answers
  6. Lesson Material - General files

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JT 15.1 - Combining Chords and Modes

The scale-tone chords of the major scale were discussed in Lesson 12.
Scale-tone chords are formed using the scale-tones of one scale only.

Here the seven scale-tone 7th chords of the C major scale.

Audio 1

We discussed the modes of the major scale in Lesson 14.
Modes are scales using the same notes as the parent (major) scale but with a different choice of tonic note.

Here once again are the seven modes which are derived from the C major scale.

Audio 2

We can combine each of the seven scale-tone chords of the major scale with the corresponding mode (which starts on the same tonic note as root of the chord).

This produces the following seven chord - mode combinations :

Audio 3

This shows that there are :

2 modes that fit a major 7th chord 1. Ionian mode (= major scale)
2. Lydian mode
1 mode that fits a dominant 7th chord Mixolydian mode
3 modes that fit a minor 7th chord 1. Dorian mode
2. Aeolian mode
3. Phrygian mode
1 mode that fits a half diminished chordLocrian mode

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JT 15.2 - Chord Function

There are two guiding rules for selecting a chord - scale combination (called a chord - scale "fit") for improvisation :

  1. Any scale that contains all the chord tones of a chord can be used for improvisation over that chord.

  2. The best choice is a scale that reflects the function of the chord.

A chord function is the role a chord fulfils in the chord progression of the song.

In many cases the chord is part of a segment of a major scale chord progression.

Audio 4
In above progression the Fmaj7 chord functions as a IV chord.
Use therefore the F Lydian mode, rather than the F major scale

The Cmaj7 chord on the other hand is the I chord (Tonic chord) of the progression.
Here the C major scale is the appropriate choice.

For the minor chords use the E Phrygian mode for the Em7 chord, the A Aeolian mode for Am7 and the D Dorian mode for Dm7.

Note that all modes selected here are derived from the same major scale.
This stands to reason, for if the chord progression reflects the tonality of one scale only, the improvisation (and the scales used for it) should do the same.

Audio 4

For example, to use an E Dorian mode (E F# G A B C# D) over the Em7 chord in above progression would produce a modulation to another key (D major), which in this case is not appropriate.

Where different modes are derived from the same major scale, the improviser only needs to think of the notes of that major scale.
The various chords played in the progression will automatically produce the 'mode sound', for all improvised notes will be heard in relation to each chord root (which is also the mode tonic !).

The preferred modes for the seven (major scale) chord functions are :

Audio 5
(Audio of C chords and corresponding C modes)
Imaj7 chordIonian mode (Lydian mode sometimes used to add spice)
IIm7 chordDorian mode (most common)
IIIm7 chordPhrygian mode (only rarely used)
IVmaj7 chordLydian mode
V7 chordMixolydian mode (other scales used to add tension)
VIm7 chordAeolian mode
VIIø chordLocrian mode (only rarely used)

The IIIm7 and VIIø chords only occur in large scale-tone chord progression segments.

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JT 15.3 - Most common Scales for Improvisation

The most commonly used scales for four of the five qualities of the C chords are :

Audio 6

The same chord - mode combinations are used for the chords with the other 11 root tones.

But remember, depending on the chord function the Lydian mode may be more appropriate for a major chord, and the Aeolian or even Phrygian mode may be preferable for a minor chord.

For improvisation over minor scale chord segments see also Lesson 17.

For more about advanced scales see the Scales Book.

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JT 15.4 - Scale for the Diminished 7th Chord

The diminished 7th chord quality is not present in the family of scale-tone chords of the major scale.


Other scales are therefore required for improvisation over this chord.

The most commonly use scale is the 8-note diminished scale discussed in Lesson 1.

Audio 7

The important thing here is that a diminished 7th chord is the scale-tone 7th chord on the tonic note of this scale. A minor or major or dominant chord can not be formed on the tonic note. There is no ambiguity about its (diminished) tonality. This makes it an ideal choice for improvisation over diminished 7th chord.

With the 8-note dominant scale the situation is markedly different.
Not only a diminished 7th chord can be formed on the tonic note of this scale, but also a dominant 7th chord, or a major or minor triad.

Audio 8

This makes this a rather ambiguous scale not characteristic of a diminished sound.
Therefore : do not use the 8-note dominant scale over diminished chords for improvisation.

Diminished chords are mostly used as short passing chords. It is therefore often easiest to use chord tones for improvisation over these chords. (See also the Scales Book.)

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JT 15.5 - Quiz

1. Name two scales used for improvisation over a major 7th chord.

2. Name three scales used for improvisation over a minor 7th chord.

3. Name one scale used for improvisation over a dominant 7th chord.

4. For which chord is the Locrian mode used ?

1. What does "chord function" mean ?

2. How are chord functions expressed ?

Identity the function of each chord in the following chord progression segments (taken from four famous Jazz standards).
1. Am7 - D7 - Gmaj7 - Cmaj7 (Autumn Leaves)

2. Am7 - Dm7 - G7 - Cmaj7 - Fmaj7 - B ø - E7 - Am7 (Fly me to the Moon)

3. Fm7 - Bbm7 - Eb7 - Abmaj7 - Dbmaj7 - G7 - Cmaj7 (All the things You are)

Which scales can you use over these chords (spell out each scale in letter names).
1. Fm7

2. A7

3. Bbmaj7

4. Eø

5. Bm7

Over which chords do you use these scales for improvisation ?
1. A B C# D E F# G A

2. C Db Eb F G Ab Bb C

3. F# G A B C D E F#

4. Bb D E F G A Bb

5. G A Bb C D E F G

Mark the Dorian mode in all keys on the
Keyboard Diagrams.

Use the formula : - t - s - t - t - t - s - t -

Write the notes and note numbers of the Dorian mode in all keys on the Scale Letters Diagrams.

Use the note numbers : 1 - 2 - b3 - 4 - 5 - 6 - b7 - 1

Quiz Answers

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JT 15.6 - Lesson Material

File Name Contents
jt15fac.gif Jazz Theory 15 - Facts sheet



Keyboard Diagrams

Manuscript paper

Scale Letters Diagrams

jt20rul.gif Chords, Scales & Modes Ruler

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© 1998 - 2008 Michael Furstner (Jazclass)