Tuesday, January 7, 2014

Book review: Creative Chordal Harmony for Guitar by Mick Goodrick and Tim Miller

As I've mentioned in my previous post, I read the new book by Mick Goodrick and Tim Miller: Creative Chordal Harmony for Guitar. In this book the authors introduce their concept of Generic Modality Compression (GMC). Since this term is not really self-explanatory (at least not for me), I was curious what it is all about.

There are actually only about 10 pages to read, the remaining pages (about 80) are examples in standard notation (no tabs). So, I've read everything, actually twice to make sure I didn't miss anything, I've looked at all the examples, and I've played through many of them. Let me first summarize what I think this book is about, and what you can find in those 90+ pages.

The basic concept is very simple and can be explained very easily. Take a heptatonic (7-note) scale and remove the root ("compression"). Now you're left with six notes. Divide these six notes into two groups of three. If you try (or if you know basic combinatorics), you'll see that there are 10 possible ways to do that. Now you have 10 pairs of three notes. Each pair, when combined, gives you all six notes of the "compressed" scale (i.e., all notes except the root). These 10 pairs of three notes can be played as three-part chords, or they can be played linearly as melodies (in any permutation, of course). That's what Generic Modality Compression is about.
So, what can you do with it? The idea is that instead of playing complete four-part or five-part-chords, you choose a chord-scale for the chord you want to play, apply the process described above, and then you play the above mentioned three-part chords (either harmonically or melodically). This will hopefully lead you to new voicings and will open up new sounds that you might not have discovered otherwise.

Let me give you an example to show you how it works in practice. If G7 is the chord over which you want to play, first choose an appropriate scale, e.g. G-mixolydian: g-a-b-c-d-e-f. If we remove the root we're left with six notes: a-b-c-d-e-f. Now we get the following 10 three-note pairs:

a-b-c * d-e-f
a-b-d * c-e-f
a-b-e * c-d-f
a-b-f * c-d-e
a-c-d * b-e-f
a-c-e * b-d-f
a-c-f * b-d-e
b-c-d * a-e-f
b-c-e * a-d-f
b-c-f * a-d-e

Each pair contains all six notes, i.e. each pair completely represents the scale apart from the root note G. You can play each of the above groups of 3 pitches as three-part chords. Note that you can use inversions and open voicings, i.e. the three-part chord a-d-f (second inversion of a D minor triad) can (and should) also be played as (from low to high)


In this way you'll get tons of three-part chords (and six voicings for each chord) to create new and unexpected sounds (and to keep you busy for a while).

Those 80 pages of the book in standard notation just contain all possible pairs of three-part chords and their inversions (close and open voicings), first for the mode C ionian (C major). After that the principle is applied to the jazz standard Stella By Starlight. For each chord in that tune, a chord scale is chosen, and the corresponding 3-part-chords are listed. You can listen to the examples on the CD, and there are also play-along tracks for you to practice. Later in the book, there are also examples for the melodic use of this concept ("Arpeggio Permuations"). This is very simple, just take the 3-part-chords from the previous pages and arrange the notes linearly, i.e. play them one after the other.

OK, that's what this book is about and what you can expect to find in it. Now I would like to make a few critical remarks. First of all, the whole GMC concept as introduced in the book is based on reducing a 7-note scale to a 6-note scale by removing the root. The motivation for removing the root appears to be the 'fact' that the root is played by the bass player, so the guitarist shouldn't bother to play it. Well, especially in a jazz context, you won't find a bass player just playing the root. Maybe the bass will play the root on the first beat of the bar (or maybe not), but anything can happen after that. If also the accompanying instruments are to be given some freedom - as is normally the case in improvised music - then all instruments are responsible for establishing the sound of the mode/chord at any given time. For this reason I think the motivation for removing the root from any 7-note scale is a bit weak. There are great sounding chords/voicings including the root (in a high register), so why not use them?

I feel that there's another problem with GMC: there is no mention of how to treat avoid notes. Avoid notes are notes in a scale which are not (traditionally) available as tensions for the related chord. E.g., if we choose C ionian (C major) as a chord scale for a Cmaj7 chord, the note F is considered an avoid note, i.e. a note which cannot be added as a tensions to the Cmaj7 chord. Consequently, if a Cmaj7 chord should be outlined using GMC, all 3-part-chords containing the note F should be avoided. But this is not done and not even mentioned in the book. Instead, all 3-part-chords containing a C are avoided, yet this is not always necessary, depending on the chord voicings played by the other instruments.

I understand that GMC restricts itself to three-part chords, but this fact is not discussed in the book. I think that 4-part chords do sound great on the guitar, and just because six notes (i.e., the compressed scale) can so beautifully be split in two groups of three notes should be no reason to leave out great sounding 4-part voicings.

Finally, while browsing through the book I got the feeling that there are too many redundant examples. E.g., all the permutations of melodic possibilities of three-part chords. I think it is obvious how to take apart a three-part chord and play its three notes linearly, in any desired sequence. The authors spend many pages on writing out all those possibilities. I would have preferred a few more pages of discussion and motivation, e.g. addressing the issues I've mentioned above (avoid notes, etc.).

On the bright side, the accompanying CD sounds great and inspires you to play through some of the examples yourself. While doing so, you will definitely discover some chord voicings which you haven't played before. What I also found inspiring was that the book showed me one more possibility to learn a tune: by figuring out all possible (three-part) voicings of the appropriate chord scales for the chord progression of the tune. This is quite some work, but it will give you a lot of freedom while playing through the changes, either harmonically or melodically. And finally, I found the book a great reading exercise. Since there are no tabs you have to read everything from standard notation. And since many of the chords are no standard triads, (sight) reading them can be quite challenging. So despite having a few critical remarks on the book's concept and its presentation, I got quite some inspiration out of it, and I discovered yet another way to study a tune.

Here a short summary:

- nice CD, some great and surprising sounds
- shows you a very thorough method to study a tune
- good reading exercise

- no mention of avoid notes
- completely disregarding the root is not sufficiently motivated
- too many pages of redundant examples, at the expense of room for discussing and motivating the concept more thoroughly
- artificial restriction to three-part chords

Also check my post on II-V-I progressions using GMC.


  1. Hello Mathius, cheers Bro

    I felt I wanted to comment regarding your review...I have been working with G.M.C for well about a year and a half....prior to starting work on that approach I had excavated many many theories....and I found this (GMC) to be an absolute embarrassment of riches......it just takes awhile to get the feel for the voicings to make them sound musical,,,

    I found no "problem" with "avoid" notes ...in fact I don't buy into the concept of "avoid" notes....and respectfully,...I would call into question the "motive" for establishing "avoid" notes as practice...

    This theory (GMC) is as sound as it gets if you know how to use it....I am from the "Ted Green" school of thought....I love to play heavy as well as jazz...

    I just wanted to give an endorsement toward the GMC idea here because I strongly appreciate it's value..

    Also I wanted to say good work Mathius....

    Keep it up Bro..your very good..and I enjoy watching and hearing you..

    I will leave a link to a sound file with myself applying some GMC.....hope you like it..


  2. Sorry...I just read your pros a cons....or plus and minuses....DUDE!.....you seem you have missed the idea of the theory (GMC)......for one....the root is extremely important in GMC theory......but when you employed the theory...you failed to have a root present at all....that is why the intended sounds are not manifesting....let me be clear...if there is no root established and "summoned"......then you are not employing GMC theory....you need to demonstrate in a Musical context....to be fair..

    sorry if I offend..that is not my intention.....but do you see my point?....the theory absolutely insists on presence of a root...rather than disregards it......that is certain..;....and as with music in general......a little rhythm wouldn't hurt....you know what I am saying?.....sheesh.....what do ya think? that you can strip away all sensible elements of playing musically....and the theory would magically produce wonderfull things?....lol

    Cheers Bro

  3. P.S. in my musical example I gave with my initial comment...you can hear me spiking the hell out of those "Avoid" notes.......and a lot of people have told me it's honey to their ears.....but then again...lots of them don't know music theory....so I guess their ears don't understand...

    1. Thanks Hugh for your comments. Fair enough you found no problem with avoid notes. What I wanted to point out is that, traditionally, avoid notes are considered an important thing, and that would already have been a good reason for the authors to at least mention them. They can of course decide to happily ignore them, if they like what they hear. I totally agree that avoid notes can sound great if used with care.

      And as for what I might have missed, I guess it's less than you think. What I was referring to is the fact that none of the voicings contain the root, and that's just the way it is. If you listen again to my examples then you can hear a bass playing the root, so obviously I take the root into account. What I found odd was just that no voicing ever contains a root, but many of them do contain traditional avoid notes instead.

      And indeed, the examples are not played in any interesting rhythmical way, because I wanted to demonstrate the sounds, instead of showing off an ingenious composition of mine. Rhythm was not the point at all, but of course I agree with you that rhythm is essential to music.

      I listened to your track, nice! After all, nobody cares what it is as long as it pleases the ears. Just keep hitting those avoid notes :)