Extended Chords

Extended chords go beyond the seventh by stacking more thirds - adding 9ths, 11ths, and 13ths.

If seventh chords add a fourth ingredient to your dish, extended chords keep layering. More complexity, more flavour - but you need to balance it carefully or the dish gets muddy.

How extensions stack

Extensions continue the pattern of stacking thirds above the seventh. The names come from counting scale degrees from the root.

The 9th is the same note as the 2nd, an octave up. The 11th = 4th up an octave. The 13th = 6th up an octave.

9th chords

The most common extension. A 9th chord is a seventh chord with the 9th added. Sounds lush and open - a staple of R&B, jazz, and neo-soul.

11th and 13th chords

The further you extend, the more notes you're layering. In practice, producers often leave some notes out to keep things clean - you don't need every ingredient in the stack.

Notice how C11 and C13 above drop the 5th. This is normal - in extended chords, the 5th is often the first thing to go because it doesn't add much character.

"Add" chords vs full extensions

A Cadd9 is different from a C9. Cadd9 adds the 9th to a triad (no seventh). C9 includes the seventh.

When to use extensions

Extended chords add sophistication. A simple triad progression can sound completely different with 9ths and 7ths layered in. But more isn't always better - sometimes a plain triad is exactly what the track needs.

Next: what happens when you replace the third entirely - suspended chords.