Minor harmony and Modal Interchange like Tord Gustavsen

I thought it would be interesting to talk about minor harmony and Modal Interchange and see how Tord Gustavsen used it in his composition Where Breathing Starts. It was originally recorded by the trio in 2003. This was Gustavsen’s debut album with the ECM label. There is a duo version with Ulrich Drechsler on clarinet from 2006.

This article considers how minor harmony is approached in jazz with reference to some of the standard texts on the subject. It is really interesting to see how the way jazz musicians think about minor harmony has changed since the 1950s.

The ECM label is based in Germany and is famous for jazz recordings with European and classical music influences featuring such artists as Keith Jarrett, Jan Garbarek, Eberhard Weber and Kenny Wheeler.

It is interesting to notice that the voicings found in this transcription are almost exclusively classical tertiary voicings (built in thirds) with inversions, rather than the typical voicings found in jazz piano from the US discussed in the article about Kenny Barron.

Other classical features of the arrangement include the use of bass lines featuring chord inversions and Mozart-style ‘Alberti bass’ lefthand arranging (see end of second A section).

This song is a tango. Tangos are usually in two sections which each repeat. The form here is AABB (16-16-16-16). The A sections are in C minor. The B sections are in C major.

What is Modal Interchange?

There are a number of terms for this concept which mean the same thing:

• Modal interchange
• Modal mixture
• Modal borrowing

You may well be familiar with the idea of using several source scales to generate the chords used from jazz tunes in minor key harmony. Nettles and Graf as well as Mulholland and Hojnacki point out that minor tunes routinely use chords from:

• Natural minor (Aeolian)
• Harmonic minor
• Melodic minor
• Dorian minor (the second mode of the major scale)

They call it ‘Dorian minor’ because it is a mode of the major scale which happens to have a minor third. Other minor modes would be Phrygian, Aeolian (the natural minor we already have) and Locrian. ‘Major modes’ are Ionian (the major scale), Lydian and Mixolydian. These last two can all be used as source scales for chords.

Unlike major tunes, minor tunes are rarely diatonic to just one scale. For this reason, some think of the combinations of these 7-note source scales into a single 9-note source scale for minor tunes. The first five notes are the same anyway, for the sixth and seventh degrees we have both major and minor (6 and 7). This amounts to the full Melodic Minor scales in its classical ascending and descending forms combined).

In 1959, Mehegan said almost all jazz tunes are in major keys and that only five or six begin and end the minor. He goes on to say that minor-key jazz had ‘evolved’ to use melodic minor (ascending) to preserve the conventional bass lines familiar from major keys (eg I VI II V), while using the harmonic minor for the inner notes of the chords. Resulting in just seven available chords for C minor:

• C-maj7
• Dø
• Eb+maj7
• F-7
• G7(b9, b13)
• Aø
• Bo7

A short, but useful list. And pretty much all we need for the minor parts of Gustavsen’s tune. But not quite complete enough for all contemporary minor jazz. For example, no C-7, F7#11, Abmaj7 or Bb7.

Dave Berkman points out that the vast majority of minor harmony chords are derived from the first three source scales above. And it is true that the only additional chord that Dorian provides is bVIImaj7 (Bbmaj7) because none of the other three scales has both Bb and A present at the same time. His list of most common minor chords is somewhat longer than Mehegan’s:

• C-6, C-maj7, C-7
• Dø
• Ebmaj7
• F-7
• G7b9b13
• Abmaj7, Ab7
• Aø
• Bbmaj7, Bb7
• Bo7

Notice that there is no B7alt on the list. This is supposed to be derived from the seventh degree C melodic (ascending) minor, and yet cannot be found by stacking thirds. Mark Levine attributes this to the limitations of traditional music theory and goes on to choose the fourth note as the third of the chord.

Jack Reilly takes a simpler approach by simply using the melodic minor ascending and descending, he derives a 9-note source scale from which all parallel minor chords can be constructed. Mulholland and Hojnacki also go on to do this calling it a composite scale combining their four into one. They also point out that there is also the Phrygian minor mode to consider if you want to justify chords containing the note b2 or Db such as Dbmaj7 when in C.

Interestingly, Mark Levine’s books only consider harmony derived from major modes and Melodic Minor (ascending). Unlike the other authors, he gives no special consideration to the harmony of minor tunes in general and how they tend to behave differently from major tunes. He effectively excludes the harmonic minor without which it is not possible to explain a traditional minor II V progression. His books are excellent in many areas, but this seems like a significant omission to me. He also makes no mention of the concept of modal interchange, not even in his chapters on reharmonisation.

I’ll aim to keep it simple by talking only about chord source scales rooted in C. The relative minor of Eb major is C minor. The natural minor is the Aeolian mode of Eb major starting on C. Because the scale contains the same notes as Eb major, and chords derive from scales, they share the same chords. But if C minor is to function harmonically as a key, we need its V chord to be a dominant seventh to provide the expected tension and release of a V I cadence. The chord on G is actually G-7. The solution is to change the mode by raising Bb to B to give us a G7 chord. This mode is called the harmonic minor and we routinely borrow this version of chord V when creating minor harmony.

That raised B natural also gives rise to a full B dim 7 chord on degree VII. So, when in the key of C major and we use B dim 7 to represent G7b9, we can consider that we are borrowing chords from C harmonic minor. This is called modal interchange (borrowing or mixture).

So, it is common to see modal interchange in both major and minor keys. And this is what we will see when we analyse this song. But some take the view that it is only called modal interchange when it is the major key borrowing because minor does it all the time.

It is important to understand that these chords from other source scales are not just parachuted in without care. Voice leading is crucial to making good music. When we listen the Tor Gustavsen play this track he makes much of the movement, say from G on a C chord to the Ab on a minor subdominant chord.

A section

Listen again ➡️to the recording⬅️.

The A section is predominantly in C minor. As explained, minor harmony already draws on a wider choice of chords than does major because of the 9-note combined source scale commonly used. The transcription in this article shows the piano part above the double bass part.

The chords of interest in this section are:

• Bars 3 and 6: G7susb9. It is voiced as F-6 or Dø over G, a slash chord.
• Bar 11: Eb+maj7. The #5 is the B. This chord can be considered to have a source scale of either of C harmonic or melodic minors. In the recording, it is voiced as a G triad over Eb in the bass—a slash-chord voicing.
• Bar 12: the B resolves to the usual Bb, making the chord Ebmaj7, but we do not hear a modulation to the relative major because this occurs in a weak place of harmonic rhythm. You can view this chord having the natural minor (Aeolian) as its source scale.

• Second time bar: F and unaltered G7 are both borrowed from C major (aka the Ionian mode) hinting at the change of key to C major to come in the B section.
• However, the G+7 and C- chords bring us back to C minor to complete the A section.

B section

Listen again ➡️to the recording⬅️.

Without preparation, the B section starts out in C major, the parallel major to the A section’s C minor. It really feels like the sun just came out.

Notice that the C major chords at the beginning of the B section are voiced as C triads with added 9th. There are no 6ths and no major 7ths. It’s a more modern sound than many jazz players use. Almost like something out of pop music.

Modal interchange chords of interest include:

• Bars 2 and 4: A minor subdominant chord is borrowed from C minor and played over a C pedal. It can be viewed as F-/C or Dø/C.
• Bar 9: F#ø. This chord has an E natural but does not naturally occur in C major. It is borrowed from the C Lydian mode.
• Bar 10: Fo7. This symmetrical chord functions as a Bo7/F representing G7b9 and is borrowed from C harmonic minor as already mentioned.
• Bar 11: The Bo7/F voiceleads perfectly to C/E confirming that we are still in C major.
• Bar 12: But then the tonic chord itself has its bass lowered to become C-/Eb signalling that we are back in C minor without any warning. The sun went behind a cloud.
• The final four bars of the first time ending are a slow minor II V confirming the return to C minor just in time to set up the surprise opening of the B section in C major on the repeat when the sun comes out again.

In those last two bars of the first time through the B section, Gustavsen allows himself a small improvised break (not shown in the transcription) which he had not done up to this point.

Listen again ➡️to the recording⬅️.

So far the B section has been about contrasting C major and its parallel minor. The genius of this composition is revealed in the second time through the B section where the relative minor (A) is also explored. The transcription below start with bar 5 because bars 1-4 are the same as the first time above:

• Bars 6-7: a V I cadence to A minor is introduced.
• Bar 9: F#ø same as the first time, unless we want to consider Am as a newly-established key (see below).
• Bar 10: this time the symmetrical Fo7 acts like a pivot chord and this time represents E7b9 to get us back to A minor rather than the G7b9 going to C major the first time.
• Bar 13: A minor has been established so I analyse the F#ø as being borrowed from A melodic minor. We see Fmaj7 which is borrowed from A natural minor (Aeolian).
• Bars 14-15: V I cadence to A minor as a very different second-time ending to the B section.
• Bar 16: The original A section theme pick-up begins again in C minor to allow the form to repeat. The jump from A minor back to C minor is unprepared and quite a shock if you don’t realise to where you have been led.

Perhaps listen again ➡️to the recording⬅️.

If you have enjoyed this article, check out my others and let me know. If you have found the insights useful, donations are always welcome. Or consider purchasing my book which analyses 230 jazz standards and distils the common harmonic features. All the links are in my link tree: ➡️https://linktr.ee/Jaelliott⬅️.

Further reading

Mehegan, J, Jazz Improvisation, vol 1, Watson-Guptil, 1959.

Mulholland, J and Hojnacki, T, The Berklee Book of Jazz Harmony, Berklee Press, 2013.

Levine, M, The Jazz Theory Book, Sher Music, 1995.

Nettles, B and Graf, R, The Chord Scale Theory and Jazz Harmony, Advance Music, 1997.

Reilly, J, The Harmony of Bill Evans, vol 2, Hal Leonard, 2010.