The Meaning of Omitted Tones Shown In The Charts
You may see labels like "No 5, 9" just below the chord diagrams. What does that mean? These labels aren't there to tell you that anything about the chord shape is "wrong". They simply indicate which tones are omitted from the complete theoretical chord.
But before diving into details right away, consider this. A standard-tuned guitar has 6 strings, and you have only 4 fretting fingers, while the largest theoretical chord, such as a C Minor 13th, has 7 tones (all the notes of the scale, slightly spread out). Even if you had 7 fingers, you'd still be limited to 6 strings—so the maximum number of unique tones you can play is 6. But it's not just about that limitation. There are also very good, specific reasons why you might choose to leave out certain tones that I list closer to the end of this section.
Now onto the interesting stuff. We don't omit just anything we like, we only omit:
- Non-guide tones
- Non-primary color tones
The key thing to remember is that the chord remains complete and functional without them, still sounding exactly as intended.
What are guide tones?
The guide tones are the root, 3rd, and 7th. When I say "3rd" or "7th", they can be either major or minor, depending on the chord type. For example, in a C7 dominant chord, the guide tones are the root, major 3rd, and minor 7th. In a Cm7 chord, they are the root, minor 3rd, and minor 7th. We collectively call them "3rd" and "7th", with the exact flavor (minor or major) determined by the chord type.
What are non-primary color tones?
A non-primary color tone is any tone whose number is lower than the chord symbol. For instance, in a Cm13 chord (which is the most extended chord) the less extended versions are Cm11 and Cm9. So, in this case, we can omit the 11th and 9th because, in a Cm13, they act as background tones rather than the foreground. The foreground tone is the 13th. In a Cm11 chord, the foreground tone is the 11th, and the 9th is in the background, so it can be omitted. Note that we can never omit the 7th, because, recall, it's a guide tone and we always retain it in extended chords.
Why do we omit some tones?
- To give space for other tones—or in other words, to remove inessential tones in favor of highlighting the ones you want. For example, if I want to play a Minor 11th chord and feature both the 9th and 11th, I can remove the 5th. Alternatively, if I want to keep the 5th, I might omit the 9th. See? It's a bit of juggling.
- To simplify the chord shape.
- To avoid clashes, such as a minor 2nd/9th interval. For instance, in chords with a #11, you might see the 5th omitted (e.g., Major 7th #11 or Dominant 7th #11).
- Due to the limitation of the number of fretting fingers.
- Due to the limitation of the number of strings.
To Include or Not to Include the Optional Note
Dashed notes indicate optional tones that can be omitted without affecting the chord's function or core sound. These are either tones duplicated in another octave, non-guide tones, or non-primary color tones.
I recommend playing the chord without them first and really listening to how it sounds, then adding them only if you like what you hear and they serve the sound you're going for.
Why I introduced them?
- Reduces the number of diagrams—one optional note would otherwise be split into 2 diagrams, two would result in 4 diagrams and so on.
- Makes it easier to see similarities between shapes when they're superimposed
Here are some scenarios where you might choose to include them or leave them out—these aren't pros and cons, just different situations you might find yourself in.
Scenarios when you would want to include:
- It makes that particular chord shape easier to play with the optional note included rather than omitted.
- You want the fuller, richer sound that comes from adding the inessential tone.
- You like it when you can strum the chord with the pick rather than fingerpick around string skips.
Scenarios when you would not want to include:
- You want to reduce note density and let the chord breathe, creating more space in the sound.
- You want to separate the bass from the chord-defining tones.
- You need a specific top voice for voice-leading to the next chord, and adding another note on top would change that (the opposite is also actually true—you might want to include it for the very same reason).
- You want to omit inessential tone(s) to highlight the main color of the chord—in other words, to add definition and emphasize your original intent.
- Including it makes the chord harder—or even impossible—to play for your current situation (hand size, finger limitations, injury, etc.).
Another goal I aimed for with these optional notes was practicality—you can add any of them without changing your hand position or rearranging your fingers. If a shape includes an optional note, it means you either have a free finger available to fret it, or you can easily bring it in with a simple barre.
Diatonic Vs Non-Diatonic—What Does It Mean?
This chart includes non-diatonic chords. I know this term can feel confusing at first, so I want to explain the difference between them in this section as simple as possible without heavy theory.
There are usually two ways we use the word diatonic, depending on context:
- Scenario 1: Can the chord be built only from the notes of a Major scale (or any of its modes)?
- Scenario 2: Can the chord be built only from the notes of a specific scale?
In the first case, we often say things like "Cmaj7 is a diatonic chord" without naming a scale. In the second case, you might see something like "CminMaj7 is diatonic to the Melodic Minor scale".
However, in practice, context does a lot of the work. If the discussion is clearly focused on the Melodic Minor scale, you can drop the phrase "to the Melodic Minor scale" entirely — it's already implied, so there's no need to repeat it.
In both of these scenarios you get an answer to the question "is this chord compatible with scale X?", or "does this chord naturally exist in scale X?". When you learn that the answer is "yes", then you know you can use this chord as a substitute for some other chord in that harmonic environment. For example, if minor 11th chord is diatonic, then you can use it as a smooth substitute for a minor 7th chord, and it will fit your musical context without breaking the sound.
One thing to watch out for is that even if a chord is diatonic to a specific scale, it doesn't automatically mean it works on its every scale degree. Recall that the way we get chords from a scale is by stacking thirds on each degree of the scale—so their position matters.
For example, in a Major scale, scale degrees II and III give you minor triads. If you keep adding thirds on top of a triad, you'll find that you can build a minor 9th chord on degree II, but that doesn't automatically mean you can freely move it to degree III. You need to verify each case in a respective reference for that scale. In our example, you'll find that degree III gives you a m7(b9) chord rather than a m9. But the point is that a minor 9th chord is diatonic to the Minor scale because it can be constructed entirely from the intervals available in that scale.
To sum it up, let's put the contrast of the two terms side by side:
- Diatonic—all chords come from the Major scale (and its modes), so they can be used freely in progressions based on either the Major or the related Minor scale.
- Non-diatonic—chords that are not found in the Major scale (or any of its modes). Using them in a Major or Minor progression will introduce "outside" notes that may sound unexpected or tense.
Note: If the word diatonic is used in the context of any other scale family, then the contrast I've outlined above still applies—you just replace the Major scale with the specific scale in question, such as Melodic Minor.
Here's one last shocking example you might not think about :) The natural Minor scale that we all know and use has one "weak spot"—it has a minor chord on its dominant V scale degree which creates a softer, less convincing resolution back to the tonic. Because of that, we often replace it with a major V chord to strengthen the pull back home. That major V is technically non-diatonic, since it introduces notes outside the scale—but it sounds great and more functional in practice, so we use it all the time.
This is to show you that there are no strict rules here. Theory just describes what already exists in music—it doesn't enforce limits. And this distinction doesn't mean you cannot use non-diatonic chord in a diatonic context—you absolutely can. Just trust your ears: if it sounds good, it works.
I hope this clarified the distinction between these two terms. The key point is this: these labels don't describe whether a chord is good or bad, common or rare. It's there to help you quickly understand whether it's compatible with the scale of your interest.
Chord Intervals Reference
The handy table below shows the chord extension depth, how each level can be modified, and the symbols used for each alteration.
Note that these are not scale degrees, but chord notation as used in chord symbols such as 7sus4 or maj7#11. For example, the symbol "7" here represents a minor 7th interval, whereas as a scale degree it would correspond to a major 7th.
The "Dominant" column shows a full stack of thirds that forms an extended dominant chord reaching all the way up to the 13th. It serves as our reference point. When you raise or lower any of these tones, that alteration gets a symbol which you can see to the left and right of this column.
Just to clarify: this chart itself isn't specifically about dominant chord alterations—it applies to all chord types. It's just that the unaltered symbols (1,3,5,7, etc.) define the dominant chord structure and serve as the baseline.
Think of the leftmost column as the extension level (or depth).
Relationship Between Scale Degrees and Intervals
0 Comments