Extended chords
Read 9th, 11th and 13th chords and know which notes matter for the bass.
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:
| 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).
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.
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.