How do I identify chord scales? (Chord scale theory)

Question

I'm confused with how to identify chord scales because there are a lot of modes and combinations I have to consider. For example, Cmaj is C Ionian, and C13 is C Mixolydian, etc., right? Basically there's a whole chart with these modes and their corresponding chords. And it's very specific. But what about chords like G7#9#5? What chord scale is that? Or E7#9? That can't be mixolydian right?? What about Dm7b5? Or C9? Or Db9#11??

I just wish there was a chart that has a complete list of all these specific chords because I'm genuinely confused.

Answer 1

I haven't had to study the chord scale theory (for which I am very greatful), but this is how I understand that the concept has to be, in order to make any sense.

You don't have to know a proper name for a scale, names are needed for talking, not for playing. And you don't have to know all scales in the world, you can make them up as you go. If a given chord only explicates three notes, you are free to choose the other four. If you can come up with any set of seven different note names that includes the written chord's tones, it should be enough. In a theory exam you might be asked to give a name for your scale.

Start from the given chord like C major and keep adding notes until you have seven pitches, according to your own personal taste, preferences, skills, imagination. Then over the written C major chord, you can play notes and chords from the scale.

For example, if you built a C Lydian scale over the C major chord, you can play alternating interleaved triads: C major, D major, C major, D major ... this technique is called "triad pairs". But like I said, you don't have to think "C Lydian" first, or at all. You can think "I have C, E and G here - what other notes would I like to have?"

Learning to answer the "what other notes would I like to have" question is what you should practice. Learn the characteristics of the different options by trying them out in songs. Do you want a Bb or a B natural to go with your C major chord? Do you know what consequences that decision has? Do you feel the differences? Try it! You build skills by practicing and trying things out, gradually, one little thing at a time. Not by memorizing huge pre-filled scale charts.

Answer 2

The idea behind chord-scales is that given a chord there is a scale that contains the chord tones, plus pitches that fill in the "gaps" between chord tones.

Given a Cmaj chord, a C major scale contains all of the chord tones (C E G) plus adds notes in between (D F A-B).

This is usual taught in a simplified manner: Cmaj (or Cmaj7) = C major scale. But the simplification can be misleading. Think of the scale as adding passing tones between the chord tones. At that level, the scale could be anything containing the chord tones. For Cmaj, we might have C D E F# G A B. That scale uses an F# "passing tone" between E and G rather than F. The F# works well if, for example, the larger context of the Cmaj chord is within the key of G major.

At the introductory level chord-scales just cover the unaltered triads and seventh chords. But one can construct scales for altered chords as well. Take the example of G7#9#5. The chord contains G B D F A# D#. For convenience, respell D# as Eb, then put the notes in scale order: G A# B D Eb F. The only gap — missing letter name — is between B and D. The gap could be filled with either C or C# according to taste or musical context.

Answer 3

The other answers have captured the essence of the process very well, so I'll try not to repeat. In the earlier stages you are more likely come come across chords such as you have asked about and they may have some more common, 'first look' scales that apply. I'll just address those you have mentioned here -

G7#9#5 - This is an altered dominant chord, it's close to a dominant chord suggesting a diminished scale. One diminished scale, the whole/half, doesn't have a major 3rd, so doesn't fit. The common diminished scale that fits over a dominant chord is the half/whole diminished scale. However, this scale doesn't have a #5, so the chord spelling can't be suggesting that. The commonly used scale for this chord is the 7th mode of the melodic minor scale, the Altered scale. It is spelled 1, b2(b9), b3(#9), 3, b5, #5, b7. I've renamed the intervals to reflect how it is commonly though of, strictly though the scale is spelled 1, b2, b3, b4, b5, b6, b7.

E7#9 - Without the 5th being specified as sharp or flat you are a bit more free, and the common choices are again the altered scale or the half/whole diminished scale. This involves altering the 5th but it's not that strong a tone in this idiom and can generally be pushed or pulled where necessary.

Dm7b5 - Is usually seen as the ii in a minor ii V i. It is generally played as the Locrian scale. Commonly however a player may use the 6th mode of the melodic minor, the Locrian nat2 scale. This scale is spelled 1, 2, b3, 4, b5, b6, b7. If this scale choice works it can sound really good, but if the natural 2 sounds awkward then the standard Locrian scale should work fine.

C9 - By default is Mixolydian.

Db9#11 - Is a Lydian dominant chord, the 4th mode of the melodic minor scale, it's scale is spelled 1, 2, 3, #4, 5, 6, b7.

All the above are 'defaults' for playing jazz in this idiom, play around with them and see what you get, but they are far from strict rules. It's up to you to choose the scales you like the sound of, and the magic little shifts of harmony, or feel, that you hear the greats make (in this idiom, think Herbie, Shorter etc.) are often when they pick one scale the first time around, then pick another the second. Or even create some tension in a minor ii V i by playing Locrian nat2 at first, settling it down to plain Locrian then moving on, or vice versa.

You can play any scale over each chord, aiming to satisfy the chord tones. Once you are comfortable with the 'defaults' suggested above then try different scales that satisfy the chord tones or even try scales that diverge from the chord tones somewhat. For example playing the D altered scale over D9 for a measure before running down in D Lydian dominant and then finishing off with the D7 chord tones, or a D mixolydian. These sideways shifts are the hallmark of the idiom and can make for very free improv, though it can be a little overwhelming at first.

There are some general starting points, the 1, 3, 5, 7 will tell you wether it's maj7, min7, dom7 or minMaj7. The upper extensions will narrow down the pool of available 'first choice' scales, and generally most alterations will be on dominant chords. On these a #5 indicates Altered Scale, a #4 indicates a Lydian Dominant scale and a #9 or b9 indicates half/whole diminished or altered. However this is not set-in-stone and a 7#5 chord may well work best simply as a Mixolydian with the 5th sharpened.

The chord spelling is usually suggesting roughly what the composer intended eg, E7#9#5 = Altered, E7#5 = Mixolydian with a sharp 5. However this can be heavily lost in translation with the realbook leadsheets, but that shouldn't be a major hinderance. To properly learn a jazz tune you should be taking into account what the melody is doing, what sounds best to you and how you have extended the previous and following chords, all in order to make your own decisions on what scale you will use. When you hear musicians seemingly leaving the written changes altogether but still sounding coherent they are essentially embarking on journeys encouraged at first by small alterations of the suggested chord/scale and then going from there (if we think of this as THIS, then think of that as THIS then we can get to a completely different key, coherently..)

In truth any chord sequence that lends itself to modal playing can be navigated in many many ways. A good one to start with is Havona by Weather Report. It's just 4 Major chords, all leaning toward Lydian, you can start by playing the Lydian scale on each, then see if the natural 4 works on any of them, then see if you can think of chord 2 as a mode of chord 1, then see if you can think of all of them as modes of each other with steps up or down. There is no right answer for this tune, like all modal playing, and it's a relatively easy playground on which to experiment.. (Just slow it down, at the original speed it's a little frantic!).

Answer 4

...I just wish there was a chart that has a complete list of all these specific chords because I'm genuinely confused.

It's confusing because chord/scale charts - at least all the teaching material I have seen - don't put chords into a diatonic/key context, which is the context for many jazz phrases.

You will see charts giving examples like this:

CHORD   SCALE
min 7   dorian
(dom)7  mixolydian
maj7    ionian

What isn't explained is a common example of that is the ubiquitous ii V I progression, which in relation to a key might be C: iimin7 V7 Imaj7, where all three chords are covered by the major scale, in that example a C major scale.

I suggest first understanding common chords in a diatonic/key context and learn how the "scales" like dorian, mixolydian, ionian, etc. are just positions/rotations/modes of the prevailing key for the phrase. In other words don't always look at each and every chords change and match a scale, look for key changes and play in key.

Just like any other style, jazz will have chromatic chord progressions where the extended sense of key isn't at play. Some of those cases still involve two chord progressions that do fit into a diatonic/key context. You can treat those as above, as diatonic, but the passages are simply shorter, they last for only two chords. An example might be: A7 Dm G7 Cmaj7 where you want to recognize the two tonal centers A7 Dm in D minor and Dm G7 Cmaj7 in C major. Rather than thinking of four chord/scales, think of two tonal centers, two keys.

Sometimes there will be chromatic passages where all the chords are chromatic. One of the very common examples being all dominant seventh chords, ex. A7 D7 G7 Cmaj7. Again you can think of these in terms of keys, but the durations are shorter. Think of those dominant seventh chords as secondary dominants to implied diatonic chords. Harmonic analysis of that passage would still identify a key, like this C: V7/vi V7/V V7 I. If we literally put the implied chords in to the passage using parathesis, it would be A7 (Dm) D7 (G) G7 Cmaj7. So, play A7 as in key Dm, play D7 as in G major, play G7 Cmaj7 as in C major.

So far you can play all of those progression by simply playing in the appropriate major or minor keys. And it's understood that "playing in key" includes all the usual chromatic embellishing non-chord tones. No one should ever have the misunderstanding that "playing in key" means literally playing only the tones of a key signature. Even "classical" music does not do that.

To make the point emphatically, one more time, so far the only thing you need to identify is major and minor keys, not a long and confusing chord/scale chart.

Eventually you will get to altered chords whose tones do not fit neatly into major/minor keys. For these chords you can learn the associated special scales or just simply arpeggiate the chord tones. There are many ways to alter chords and it can become confusing. Keep in mind that chords with dominant function are the typical altered chords. Fully diminished seventh chords can be treated a similar way. Common scales to use for these chords are the altered scale, the diminished scales, and whole tone scale.

If you don't already know, the altered scale is the seventh mode of the melodic minor scale. Knowing that can help a lot to aid memorization and fingering. If you know how to play all the minor scales (and you should), then you already have the technique needed to play the altered scale.

This covers a huge amount of real world harmony.

It requires you to understand and play in:

• understanding/identifying chords in context of keys
• major keys
• minor keys
• altered scales
• diminished scales
• whole tone scales

...Or Db9#11??

This should get special attention. When you see a #11 or I suppose a #4, it's basically conveying in some sense of lydian. That sort of works against the diatonic/key approach. You will see it less in early jazz styles. Rather than taking the diatonic/key approach the lydian dominant scale is the thing to use. Yikes! yet another "scale". One way to not get overwhelmed by this scale is to recognize it as the fourth mode of the melodic minor scale. So, that's two "scales" you "already know" - the altered scale and the lydian dominant scale - if you already know your minor scales.