Bandcoach and the other three guys on here (you know who you are),
Here are some issues I have that kinda been bugging me for a bit. Decided to do this as an open thread than a PM since it might be helpful for others. I won't see my instructor until next week so I wanted to ask here for clarification.
1. Available Tensions: On a tune I am working on (My Funny Valentine), the first two measures of the B section are in the key of Eb major [Ebmaj7--Fmin7][Fmin7--Gmin7]. Now, I like extending my 7th chords to the 9th. I wanted to change the Gmin7 to a Gmin9, but my instructor hit me with the "A ninth on a chord functioning as a iii chord will make the chord nondiatonic since A natural is not in the key of Eb major". I thought I was clued up on my tensions and alterations, but apparently not since up until this time, no one ever told me to take the chord function into consideration when adding these bad boys. Help me understand tensions and alterations as they relate to chord function.
first up I get the chords as Ebmaj7 / Fm7 / | Gm7 / Fm7 / (Straight from the lead sheet found in the Hal Leonard paper back songs Jazz Standards page 174)
Secondly the Gm7 is already tensioned with the Eb in the melody so is in effect an Ebmaj9, although we would classify this as Gm7b13 which makes it an Aeolian mode chord; adding the #11 (if we assume the A instead of the diatonic Ab) to me is kosher practice - yes we are in the relative major of C minor here, but so what?
However, to paraphrase Ted Pease (former chair of composition at Berklee) we can extend the Gm7 to a Gm7b9 and have a phrygian modality briefly which also keeps the chord to a diatonic
a line from his book on jazz composition (
Amazon |
Book Depository |
Abe Books)
| Chord type | b9 | 9 | #9 | 11 | #11 | b13 | 13 | sus4 | Maj7 | #5 | b5 |
|---|
| Minor 7 | phrygian | / | | / | | Aeolian | Dorian | (11) | | | |
|---|
[
the table is littered with extensions that are permitted and those that have a context within a specific modality or are even described as rare (the maj7#9 and maj7#5 are the only two that fit this last category)
some other sources that have similar conceptual ideas about permitted tensions
Psychopompos: Chord Tensions and Chord Tension Charts - this set of charts seems to be based on scale tone extensions but is somewhat arbitrary in its naming of the tension interval, i.e. extension above chord v7 (i.e. Gm7 in our context) should have the 9th noted as b9 (i.e. its relative distance above the root of the chord is a minor 9th not a major 9th) but is shown only as 9...
Chord Tensions - this is little too glib and really avoids the nub of the problem - what extensions for what chords based on chord function
Jazz Guitar Chord Theory Part 3: Tensions - some strange language (disharmonic instead of inharmonic) but otherwise a good primer on major tonality chord extensions
Avoid note - Wikipedia, the free encyclopedia - useful as it describes in detail something that was mentioned in the link above - the avoid tone and explains why your prof is talking about the major 9th interval in his conversation with you, as the minor 9th interval is deemed an avoid tone
Guitar Lessons, Interviews, News, Reviews, & More | Guitar Messenger – A Lesson On Tensions: Can You Paint With All the Colors of the Jazz Chord? - ignore the error of calling the octave plus 7th a 15th. the rest is very nice and covers lot of ground but is light on explaining adding tensions by chord function
Tips & Tricks: The Theory of Available Tensions - short sharp distinctive and whilst ignoring specific discussion of function, it can be educed from what is given i.e. m7 cannot have the b9 above it but can have 9, 11, 13 (it even interdicts using b13 above, which we already know to be a melodic tension in eh passage under discussion)
2. Modal Mixture: Yup, got tripped up on this one. Never quite understood it from the way it was explained to me. I know that when you borrow a chord from the parallel key you're in, this is modal mixture-right? But then, for example, when harmonizing the natural minor scale, we create that strong pull to the i by raising the leading tone and thus "borrowing" the V7 of the harmonic minor key. Is this correct? I get confused by "modulation" and "modal mixture".
Just need some clarification on these two issues. Thanks in advance.
modal mixture and modal interchange are synonymous: borrowing chords from parallel major/minor keys and modes.
I have written about this at length elsewhere at fp but here is the nutshell version
| Scale/modality | Structure | Ex on C | Scale tones -> | 1 | b2 | 2 | b3 | 3 | 4 | b5 | 5 | b6 | 6 | b7 | 7 |
|---|
| Major | 1-2-3-4-5-6-7-8 | C-D-E-F-G-A-B-C | I | - | ii | | iii | IV | - | V | - | vi | - | viib5 |
|---|
| | | C | | Dm | | Em | F | | G | | Am | | Bmb5 |
|---|
| Dorian | 1-2-b3-4-5-6-b7-8 | C-D-Eb-F-G-A-Bb-C | i | - | ii | bIII | - | iv | - | v | - | vib5 | bVII | - |
|---|
| | | Cm | | Dm | Eb | | Fm | | G | | Amb5 | Bb | |
|---|
| Phrygian | 1-b2-b3-4-5-b6-b7-8 | C-Db-Eb-F-G-Ab-Bb-C | i | bII | - | bIII | - | iv | - | vb5 | bVI | - | bvii | - |
|---|
| | | Cm | Db | | Eb | | Fm | | G | Ab | | Bb | |
|---|
| Lydian | 1-2-3-#4-5-6-7-8 | C-D-E-F#-G-A-B-C | I | - | II | - | iii | - | #ivb5 | V | - | vi | - | vii |
|---|
| | | C | | D | | Em | | F#mb5 | G | | Am | | Bm |
|---|
| Mixolydian | 1-2-3-4-5-6-b7-8 | C-D-E-F-G-A-Bb-C | I | - | ii | - | iiib5 | IV | - | v | - | vi | bVII | - |
|---|
| | | C | | Dm | | Emb5 | F | | G | | Am | Bb | |
|---|
Aeolian
(Natural minor) | 1-2-b3-4-5-b6-b7-8 | C-D-Eb-F-G-Ab-Bb-C | i | - | iib5 | bIII | - | iv | - | v | bVI | - | bVII | - |
|---|
| | | Cm | | Dmb5 | Eb | | Fm | | G | Ab | | Bb | |
|---|
| Harmonic minor | 1-2-b3-4-5-b6-7-8 | C-D-Eb-F-G-Ab-B-C | i | - | iib5 | bIII#5 | - | iv | - | V | bVI | - | - | viib5 |
|---|
| | | Cm | | Dmb5 | Eb#5 | | Fm | | G | Ab | | | Bmb5 |
|---|
| Melodic minor asc | 1-2-b3-4-5-6-7-8 | C-D-Eb-F-G-A-B-C | i | - | ii | bIII#5 | - | IV | - | V | - | vib5 | - | viib5 |
|---|
| | | Cm | | Dm | Eb#5 | | F | | G | | Amb5 | | Bmb5 |
|---|
we can add to this template the ideas of tonic, sub-dominant and dominant families of chords, to whit
anything based on scale tone 1, b3/3 and 6/b6 is a tonic family chord
anything based on scale tone b2/2 and 4 as well as V7sus4 is a sub-dominant family chord
anything based on scale tone 5 and 7 as well a V7sus4 is a dominant family chord
thus we can group chords into three families like so:
| tonic | sub-dominant | dominant |
|---|
| Major | I-iii-vi | ii-IV | V-viib5 |
|---|
| Dorian | i-bIII-vib5 | ii-iv | v-bVII |
|---|
| Phrygian | i-bIII-bVI | bII-iv | vb5-bvii |
|---|
| Lydian | I-iii-vi | II-#ivb5 | V-vii |
|---|
| Mixolydian | I-iiib5-vi | ii-IV | v-bVII |
|---|
| Aeolian (Natural minor) | i-bIII-bVI | iib5-iv | v-bVII |
|---|
| Harmonic minor | i-bIII#5-bVI | iib5-iv | V-viib5 |
|---|
| Melodic minor asc | i-bIII#5-vib5 | ii-IV | V-viib5 |
|---|
where it gets really interesting is in things like sub-dominant minor modal interchange; in our example above this would mean moving from F to Fm, and then substituting a chord that contains the active F and Ab tones for that Fm, such as Db (bII). In a progression like C-F-Fm-C this becomes C-F-Db-C instead of the more often used C-F-Ab-C (Ab is the relative major of Fm)
try these links as well
How to Use Modal Interchange and Borrowed Chords on the Guitar - For Dummies - cool except that they have allowed an s to creep into some of the chord names and they have omitted the jazz minor (aka ascending melodic minor)
Modal Interchange (Modal Mixture) and Neighboring/Parallel Keys | Harmony Central - interesting yet incomplete presentation followed by this far more in depth presentation
Modal Cadences in Modal Interchange which is much more coherent presentation
order his book here
Chord-Scale Theory and Linear Harmony for Guitar: Creative Tools for Improvisation and Composition in Contemporary Music Jonathan "JonnyPac" Pac Cantin
