# Altered chords

*Module 14 · Lesson 2: Beyond the key · BazzLow*

> Recognise altered dominant chords and know the bass's role over them.

Before this lesson: [14.1 Extended chords](https://bazzlow.com/en/beyond-the-key/extended-chords/)

Jazz players love to add tension to a dominant chord just before it resolves. The notes they add are called alterations.

## Altering a dominant

**Altered chords** raise or lower the 5th or the extensions of a **dominant 7th** chord: ♭9 and ♯9; ♭5 / ♯11; ♯5 / ♭13. From C7:

*C7 and its common alterations, with the note each one adds.*

| Chord | Added note | Notes |
| --- | --- | --- |
| C7 | — | C E G B♭ |
| C7♭9 | D♭ | C E G B♭ D♭ |
| C7♯9 | D♯ | C E G B♭ D♯ |
| C7♯11 | F♯ | C E G B♭ F♯ |
| C7♭13 | A♭ | C E G B♭ A♭ |

C7alt, an **altered dominant** (written **alt**), means a dominant 7th with altered 5th and/or 9th, and **no** natural 9, 11 or 13. The exact choice is up to the chord player.

Altered tones add tension to a V7 chord **before it resolves** (V7alt → I). They are common in jazz, less so in pop and rock.

## For the bass

Play the **root**, and possibly the 3rd and ♭7, which do not change. Avoid the natural 5th and 9th over an altered chord, because they clash with the altered notes the other instruments play.

This lesson is an overview. Full use of altered harmony is beyond the course.

## Try it

Over G7♭9 → C (or simply the roots G → C), play G B D F then land on C. The chord players’ alterations do not change your note choice here.

## New terms

- altered chord
- altered dominant
- alt

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