Extended Chords: 9th, 11th and 13th Voicings for Neo-Soul

What are extended chords?

Extended chords are seventh chords with more thirds stacked on top. Open Music Theory describes them as superimposing thirds beyond the seventh above the root, which produces the 9th, 11th and 13th.^[1] Stack one more third after the 13th and you are back at the root, so 13 is as far as the system goes.

The numbers look scary but the notes are familiar. A 9th is the 2nd scale step, an 11th is the 4th and a 13th is the 6th, just placed an octave higher. The table uses C as the root.

One convention causes most of the confusion. In chord symbols, the highest extension implies the ones below it, so C13 technically includes the 9th and 11th. Open Music Theory adds that those implied notes are not necessarily played, and usually some are left out.^[2] A chord symbol tells you the color, not a list of keys to press.

What is the difference between add9 and 9 chords?

A 9 chord contains a seventh under the ninth; an add9 chord is just a triad with the ninth added and no seventh. Open Music Theory's example: Cadd9 is a C major triad with a D above it, while C9 implies the seventh underneath as well.^[2]

The seventh changes the flavor completely. Add9 sounds bright and pop-friendly, while a 9 chord brings in the jazz and soul weight of the seventh. The plain symbol "9" also means a dominant chord with a flat seventh, which trips up a lot of producers who expected a major seventh.^[3]

Voice an add9 with the 2nd right against the 3rd (D next to E) and you get the cluster Steely Dan nicknamed the "mu major", a way to enrich a major chord without making it sound like a jazz chord.^[4] Keep the third in; without it you have a sus2 chord instead.

Which notes do you leave out of 9th, 11th and 13th chords?

Leave out the fifth first, let the bass carry the root, and never stack a natural 11th on top of a major third. A full C13 has seven notes, which is too many for a clear keys part and far too many above an 808.

• The fifth The safest omission. In classical practice the fifth is the note typically dropped from a dominant ninth, leaving root, third, seventh and ninth.^[3]
• The root If the bass or 808 plays it, the keys do not need it. Open Music Theory treats the 9th as displacing a doubled root, which is exactly what rootless voicings do.^[1]
• The third, when an 11th is present A perfect 11th forms a harsh minor ninth against the major third of major and dominant chords, so the third is often omitted.^[5] On minor chords the 11th sits a whole step above the minor third and blends easily, which is why m11 is so common.
• The 11th, in a 13th chord Because the 11th clashes with the third by a semitone, dominant and major 13th voicings customarily leave it out, and often drop the fifth and ninth too.^[6]

Two rows deserve a note. The Cm11 voicing is the "So What" shape from the Miles Davis tune, three perfect fourths topped by a major third, which Wikipedia describes as essentially a minor eleventh chord.^[7] And C11 without its third and fifth is written Bb/C, the same sound as C9sus4.^[5]

How to voice extended chords in the piano roll

Keep the root low, the third and seventh in the middle, and the extensions on top. Open Music Theory advises leaving extensions in the upper registers, because close intervals in a low register sound muddy.^[8] The steps below build a neo-soul ii-V-I in C: Dm9, G13, Cmaj9.

1. Program the roots
   Put D2, G2 and C2 on the bass or 808, one bar each. The keys part will not play roots at all.
2. Voice Dm9 without its root
   Keys F3 A3 C4 E4: third, fifth, seventh, ninth. This four-note shape sits right in the warm middle of a Rhodes.
3. Move to G13 by one semitone
   Keys F3 A3 B3 E4: seventh, ninth, third, thirteenth of G. Only C moved, down to B. F, A and E all hold.
4. Resolve to Cmaj9
   Keys E3 G3 B3 D4: third, fifth, seventh, ninth of C. F falls to E, A to G, E to D, and B holds.
5. Check the lowest keys note
   Nothing in the keys part should sit much below E3 with notes this close. If the loop sounds cloudy, raise the whole keys part an octave before touching EQ.
6. Shape the performance
   Roll the chord upward over a few ticks and let the top note hit slightly harder. Extended chords sound expensive when played, and cheap when stamped.

Notice how little moves. Extended chords share many notes, so they reward smooth connections; the method is covered step by step in voice leading for producers. If you are new to the underlying four-note shapes, start with seventh chords for R&B and lo-fi.

Neo-soul, jazz-house and gospel voicings to try

Each style leans on a different extension: neo-soul on maj9 and m9, jazz-house on m11 and stacked fourths, gospel-flavored beats on sus and 13th chords. The voicings below are starting points written bottom to top.

The sus-to-13 move

The gospel rows work because C13sus4 and C13 share Bb and A and differ by one falling note: the 4th (F) drops to the 3rd (E). That single semitone is the whole emotional payoff, and the same trick turns Bb/C into C9 while Bb and D hold. Place it on beat 3 or 4 of the bar before a hook and let the drums leave room for it. For full genre context, see soulful house with gospel chords and how to make neo-soul beats.

When are extended chords too much for a beat?

Extended chords become too much when they fight the vocal or the 808 for space. Five or six notes spread over two octaves fill the midrange where a singer lives, so the richer the harmony, the more careful the arrangement needs to be.

• Leave the top for the topline If a vocal is coming, cap the keys a few semitones below the singer's main range, or drop the top extension during verses and add it back in hooks.
• Let the 808 own the root Rootless voicings exist for this. A keys root doubled against a sliding 808 is the fastest route to low-mid mud.
• Use extensions as color, not density One m9 chord in a loop of plain m7s can say more than four stacked 13ths. Save the biggest chord for the turnaround.
• Check sample flips Soul samples often contain their own extensions. Match your added keys to what the sample already plays, or they will rub in unexpected places.

For a house angle on the same harmony, read how to make Kaytranada-style house, where jazzy chords sit over broken grooves.