# Modes and chords

*Module 13 · Lesson 4: Modes · BazzLow*

> Match each diatonic seventh chord with its mode, and know when the choice matters for the bass.

Before this lesson: [13.3 Relative and parallel modes](https://bazzlow.com/en/modes/relative-and-parallel-modes/) · [10.3 Diatonic seventh chords](https://bazzlow.com/en/seventh-chords/diatonic-seventh-chords/)

A mode is a scale; a chord is a few of its notes. Connecting the two tells you which scale to play over each chord.

## Each chord has a mode

Each diatonic seventh chord (lesson 10.3) is the 1-3-5-7 of the mode built on the same degree:

*Each diatonic seventh chord and the mode on the same degree.*

| Chord | In C | Mode |
| --- | --- | --- |
| Imaj7 | Cmaj7 | Ionian |
| ii7 | Dm7 | Dorian |
| iii7 | Em7 | Phrygian |
| IVmaj7 | Fmaj7 | Lydian |
| V7 | G7 | Mixolydian |
| vi7 | Am7 | Aeolian |
| viiø7 | Bø7 | Locrian |

So a mode is a chord’s tones (1 3 5 7) plus the notes in between (2 4 6, or their alterations). The **chord tones are the same** for several modes. Three minor modes all fit a m7 chord: **only 2, 4 and 6 tell them apart**. These notes are the **colour notes** (or tension notes), and the scale that fits a chord is its **chord scale**.

> **Diagram:** Dm7 and its Dorian colour notes: the chord tones D F A C are in color; the colour notes E (2), G (4) and B (6) are grey. D at fret 5 on the A string, then E and F and G on the D string, A B C on the G string, and D at fret 7.

## Choosing the mode

- In a key, use the mode of that degree: Dm7 as ii in C → Dorian; Am7 as vi → Aeolian.
- Over a dominant 7th chord, Mixolydian is the default, because it has the chord’s ♭7.
- If the melody or harmony makes a 2, 4 or 6 audible, the bass must agree with it.

For a bass line built from chord tones and pentatonic notes, the choice often makes no difference: the minor pentatonic (1 ♭3 4 5 ♭7) fits Dorian, Aeolian and Phrygian alike. It matters when the line uses the 2nd or the 6th.

## Try it

Over a held Dm7 (or a D drone), play D Dorian, then D Aeolian. Only B against B♭ changes. Decide which one fits a C major context, where B is natural.

## New terms

- chord scale
- colour note (tension note)

Page: https://bazzlow.com/en/modes/modes-and-chords/