# Extended chords

*Module 14 · Lesson 1: Beyond the key · BazzLow*

> Read 9th, 11th and 13th chords and know which notes matter for the bass.

Before this lesson: [10.1 The four main seventh chords](https://bazzlow.com/en/seventh-chords/four-seventh-chords/) · [4.6 Compound intervals](https://bazzlow.com/en/intervals/compound-intervals/)

Chord charts often show symbols like C9 or C13. They look scary, but for a bassist they mostly mean the same thing as the plain chord underneath.

## Stacking more thirds

**Extended chords** keep stacking thirds above the 7th: the **9**, the **11** and the **13**. These **extensions** are the 2nd, 4th and 6th an octave higher (lesson 4.6). From C:

*Extended chords from C. Notes in brackets are often left out.*

| Chord | Formula | Notes |
| --- | --- | --- |
| C9 | 1 3 5 ♭7 9 | C E G B♭ D |
| Cmaj9 | 1 3 5 7 9 | C E G B D |
| Cm9 | 1 ♭3 5 ♭7 9 | C E♭ G B♭ D |
| C11 | 1 (3) 5 ♭7 9 11 | C (E) G B♭ D F |
| Cm11 | 1 ♭3 5 ♭7 9 11 | C E♭ G B♭ D F |
| C13 | 1 3 5 ♭7 9 (11) 13 | C E G B♭ D (F) A |

A plain number (9, 11, 13) **includes the ♭7**: C9 is a dominant chord. With a major 7th the symbol says so (maj9, maj13).

> **Diagram:** C9: C E G B♭ D.

## Add chords

**Add chords** add a note **without the 7th**: Cadd9 is C E G D; C6/9 is C E G A D.

## What is actually played

Not every note is played. Players leave out the **5th**, which adds little, and often the **11th** in dominant and major chords, because it clashes with the major 3rd. In a C11 they leave out the **3rd**, for the same reason. A C11 played this way sounds almost the same as B♭/C (B♭ D F over a C bass), and is often written that way. The notes played above the bass form an **upper structure**.

## For the bass

The **root** and the overall chord type are what matters. The extensions belong to the upper instruments. A bassist playing 9ths or 13ths on strong beats easily muddies the sound; use them as passing or colour notes, if at all.

## Try it

Over a C9 (or a C7 drone), play a 1–3–5–♭7 arpeggio, then add the 9 (D) as a passing note between 1 and 3: C D E G B♭. Hear how the 9 colours the chord without changing it.

## New terms

- extended chord
- extension
- add chord
- upper structure

Page: https://bazzlow.com/en/beyond-the-key/extended-chords/