In this blog, we dive deeper into how harmony works by looking at the chords commonly used in jazz and pop: the ninths, elevenths, and thirteenths, and all of their variations. Each of these magic chords can be built by simply stacking more thirds onto a seventh.

9th, 11th & 13th Chords - How They’re Put Together


In our introductory chord blog (if you haven’t yet, we recommend giving it a read before tackling this blog), we explained how chords are built, described what intervals mean when it comes to chords, and revealed that the third interval lies three notes along from the root note – e.g. the interval between a C and E, or an E and G. The first is an example of a major third, while the second is an example of a minor third. Chords are basically built out of thirds. The C-major chord, for instance, is made up of a C, E, and G, which includes a major third (between C and E) and a minor third (between E and G). Now, we can actually take these chords and ‘stack’ on even more thirds. So, when we travel three notes up from the G, we come to the B. In a C-chord, the B is referred to as the seventh, since it’s seven notes away from the C. Now, the distance between the G and B is a major third, but we can also turn it into a minor third – G to Bb. A C-chord that includes a minor seventh is referred to as C7. ‘7’ chords are normally called ‘dominant’ seventh chords and are very commonly used. By going further and stacking on more ‘thirds’, we get 9th, 11th, and 13ths. For example, we can take our C-chord and stack on a D, F, and A. We can’t stack any further than that, since we’ll be coming back to our root note – C. Stacking up to the seventh is as common in pop music as it is in jazz, and while stacking up to the 9th, 11th, and 13th happens a lot in jazz music, it’s actually also becoming much more common in pop as well.

9th, 11th & 13th Chords - How They’re Put Together

Intervals, counted from C (2 = major second, 3 = major third, 4 = perfect fourth, 5 = perfect fifth, 6 = major sixth, 7 = major seventh, 8 = octave, 9 = ninth, 11 = eleventh, 13 = thirteenth)

The 9th Chord

We’ll start with the dominant seventh chord, like the C7 which is built out of notes C, E, G, and Bb (so, the root, major third, perfect fourth, perfect fifth, and the minor seventh). Now, we’ll add the ninth. The ninth is counted as a perfect octave and a major second up from the root note (see the piano keyboard above for an example). Counting up from the C, this will bring us to a D, giving us a C, E, G, Bb, and D chord – otherwise known as the C79 chord. A 9th chord will always include a seventh (7), so in principle you don’t always need to notate the ‘7’. While you’re likely to come across the chord notated as C79 as well as just C9 – most of the time, it’ll just be notated as C9. Composers can also choose to notate a 9th chord without the 7th – so the seventh isn’t played. For example: C, E, G, D. To indicate that the seventh shouldn’t be played, the chord can be notated as Cadd9 (where ‘add9’ stands for ‘added 9’). In funk music, you’ll find that 9ths are pretty much used as a rule – just listen to a little James Brown. The ninth adds some extra colour to a chord, but without giving the chord a ‘resolved’ feel because it’s a scale-specific note, and the ‘resolution’ of a standard 9th chord lies in the minor seventh. In the 9th chord above, we have simply added a ninth to a dominant seventh chord (so C7 is turned into C79), but you can also add a ninth to a ‘major’ seventh chord. Major seventh simply means that the chord includes a major seventh. Sticking with our example, that means we get a chord made up of C, E, G, and B (notated as Cmaj7) instead of a chord made of C, E, G, and Bb. When we build the Cmaj79 chord, we get C, E, G, B, and D, which is usually notated as Cmaj9 or even CΔ9. The 7 doesn’t need to be notated because the addition of ‘maj’ (Δ) already indicates a major seventh.

Flat 9th & Flat 10th

You can give the 9th in a dominant seventh chord a more resolved feel by lowering or raising the ninth by a semitone to give it a harmonic function. By lowering the 9th by a semitone, the chord becomes a diminished (or flat) 9th. So, C79 (C, E, G, Bb, and D) becomes C7b9 (C, Eb, Bb, Db). Because the dominant seventh chord is commonly used on the fifth step, this also applies to the diminished 9th. In the C-major key, this becomes the G7b9 (G, B, D, F, Ab) where the A♯ is the diminished 9th. A diminished 9th chord has masses of ‘resolution’ to it, since it has a kind of natural pull back to the root chord. In this case, the root note is the G of C-major (E, E, G). There are three lead notes in G7b9 (G, B, D, F, Ab), where the B naturally wants to be followed (or resolved) by the C; the F wants to be resolved by the E; and the A♯ wants to be resolved by the G.

Of course, you can also raise the ninth by a semitone, giving you an augmented (sharp) chord, so G9 (G, B, D, F, A) becomes G7#9 (G, B, D, F, A♯). Most of the time, this kind of chord is notated differently, as a 7flat10, or diminished 10th, making it a G7b10 (G7 flat 10) chord. Just like the 7flat9 chord, the 7sharp9 (or 7flat10) has masses of resolution to it, usually because of the diminished 9th. The 7flat10 chord (which Jimi Hendrix was a big fan of) has a character of its own. As soon as you get familiar with it, you’ll be able to pick it out of a song immediately. This chord contains a major third as well as a minor third that kind of rub against each other – an effect that a lot of blues music takes advantage of. While the rhythm section plays a dominant seventh, like C7 (C, E, G, Bb), the pianist or guitarist might play around with the C blues scale, which includes the blues note Eb (a minor third), so the Eb rubs up against the E of the C7 chord. Although the harmonic function might differ, this combination has a sort of ‘flat 10th’ feel. The sharp 9th (flat 10th) usually comes up in combination with the flat 9th. However, you can’t really play a sharp 9th (flat 10th) against a 9th, or a flat 9th against a 9th. It’s not necessarily forbidden, since nothing is forbidden when it comes to music, but the combo will sound strange. The same occurs when you combine a maj7 with a sharp 9th (flat 10th), and a maj7 and flat 9th.

The 11th

Moving on, let’s add another level to our stack. Stepping a third interval up from the 9th, we get to the 11th. The 11th is an octave higher than the perfect fourth. If the root note is C, then the 11th will be the F. But, with 11th chords, there’s something wrong – if you play a major chord with a 7th (so, C7 or Cmaj7), the 11th won’t fit. The 11th (in this case the F), clashes horribly with the third (the E). This is why, when stacking a major chord, we shift the 11th up by a semitone, turning it into an 11th sharp chord, so a C7#11 (C, E, G, Bb, D, F#) or a Cmaj7#11 (C, E, G, B, D, F#). Despite the non-scale-specific F#, this chord sounds mellow and restful.

Most of the time, combining a maj7 chord with a sharp 11th sounds really good. When it comes to minor chords, you add a standard 11th, since the 11th doesn’t clash so horribly with the minor third of the minor chord, so you can make (for example) a Cmin711 (C, Eb, G, Bb, D, F). In this chord, the minor third is the Eb and the 11th is the F. The F is also part of the C-minor scale, and incidentally, sevenths are seldom used on the first step when playing in a minor key. If you want to add a normal 11th (in other words, a 4th) in a seventh chord, but don’t want to turn it into a minor chord, you can make a sus4 chord. In the case of C, you’d get a C7sus4 (C, F, G, Bb), where the minor third (the E) has been replaced by the 4th (= 11th), so the F.

The 13th Chord (and 6th Chord)

And now we come to the final stackable third: the 13th. This note is an octave higher than the major 6th, as seen from the root note. If the root note is a C, then the 13th will be the A. In 13th chords, a 7th (major or dominant) is always played. So here, Cmaj13 becomes C, E, G, B, D, A, and C13 becomes C, E, G, Bb, D, A. If you don’t want to play the seventh, then you’re actually playing a C6 chord (C, E, G, A), which as you can see, is a scale-specific chord and, while it adds a little extra colour to a normal major chord, it isn’t as exciting. Chords with a 6th and 9th are also played, like the C69 (C, E, G, A, D), but going back to the 13th chord, there must always be a seventh included, otherwise, you’re just playing a 6th chord. The 7th doesn’t need to be included in the notation, as in the Cmaj13 chord or C13 chord. Sometimes you will see the 7th notated (as in C713) but it’s really not necessary since it’s a given. 13th chords will often also include a 9th, but you’ll rarely ever see this notated, and while combining it with a sharp 11th isn’t common, it is possible. The sharp 11th, in this case, will be notated.

The added 13th doesn’t add any extra ‘resolution’ to a chord, but just like the 9th, adds colour. You can definitely give a dominant 7th chord some extra ‘resolution’ by adding a 13th and lowering it by a semitone to give it a harmonic function – then you get a flat 13th chord. So Gb13 becomes G, B, D, F, A, Eb. If we’re playing in the C-major key, then the leading note (Eb) will want to resolve to the third (E) of the C-major chord or to the 9th (D). The expansion of a minor seventh chord with a 13th is not all that common, by the way.

Further Than Thirteen?

Can you also make a sharp 13th chord? Unfortunately not, since the sharp 13th is actually a kind of augmented 6th – in other words: the same sound as a minor 7th. But what happens when we continue stacking after the 13th? That actually makes no sense, since you’ll just come back to the root note. So, what about the 14th? This has already been added to the chord, since the 14th is actually the minor 7th or major 7th. So, it all stops at the 13th. Of course, you can now derive other chords from all of the chords that we’ve looked at and create something beautiful. While the chords won’t have any harmonic function, they can be used to paint with sound. Play around with an augmented chord and maybe throw in a 7th; maybe build a C+maj7 (C, E, G#, B). It sounds strange, exciting, and clashes horribly, and the chord that can be used to follow it and resolve it is unclear, so it has no harmonic function. In any case, a chord like this one is great when composing things like film soundtracks since it can stand alone and create a very specific feeling on its own. Also, the 7th included in many blues chords is added more for colour than it is for harmonic function.

More Interesting Stuff

Chord Voicing

You don’t have to play every note of a chord, especially with extended chords which can can sound ‘smeared’ out and unpleasant, so it’s much nicer to keep the sound as open as possible. You can do this by spreading out the played notes and leaving out any unnecessary notes. So, the perfect fourth is a note you can leave out without worrying about it. If you’re playing with a bassist, then you can also leave out the root note, since the bass will take care of it for you. The sound of a chord depends on how the notes are ‘laid down’. This is referred to as the voicing. Voicing has two functions, the first being to give the chord a nice and open sound, and the second is to ensure that you’re not having to make any big jumps between chords. So, make sure to lay chords as close together as possible, so that you don’t need to shift your fingers too far to play the next chord. The highest notes of the chords in particular should be close together, which doesn’t just make it more comfortable to play, but makes all of the chords sound much nicer and far more ‘laid back’ when played together.


In this blog, we’ve explained how you can raise or lower a 9th, 11th, and 13th by a semitone. This way, you’re kind of borrowing notes from other scales and stepping outside of the key. This is called altering. An altered chord usually occurs on the fifth step, and you’re free to choose the note you want to alter.

Strong & Exciting

Just to try it out: play a D-major chord (D, F#, A) with a C as the bass. This is a classic jazz trick, and makes the chord sound immediately strong and exciting. Another nice jazz trick is to play a C-major chord with the left hand and play a D-major chord with the right hand – so an octave higher, or C-major with an added 9th, sharp 11th, and 13th.

All 9th, 11th, and 13 Chords

In the table below, you can see all of the chords that we’ve covered. Click on the image to expand it.

9th, 11th & 13th Chords - How They’re Put Together

See Also….

» Music Books
» Keyboard Instruments
» All Musical Instruments & Accessories

» Chords: Theory and Chord Symbols
» How to play basic piano chords
» Learn to Play Ukulele in 3 Easy Steps!
» Learning To Play Guitar Chords For Beginners
» Learning to Read Music: The C-Major Scale
» Reading Music: Rhythm, Tempo & Measure
» The Pentatonic Scale: Easy to Learn
» Reading Music: Rhythm, Tempo & Measure
» The Pentatonic Scale: Easy to Learn

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