What scale to play over each chord: a cheat sheet
Which scale fits a major, minor, 7, maj7 or m7 chord — and why the answer depends on the chord’s job in the song, with the ii–V–I as the worked example.
Updated
"What scale goes with this chord?" has a short answer and a better one. The short answer is the cheat sheet below. The better one is that it depends on what the chord is doing in the song — and once you see why, you'll rarely need the cheat sheet.
The cheat sheet
Here it is for chords on C; every other root works the same way, moved up or down the neck. Click any chord or scale to see it on the fretboard.
The "start with" column is always safe: a pentatonic or a scale that contains every note of the chord. The others add colour — and each one fits best when the chord has a particular job in the key.
Why the chord's job matters
Take the chords of C major: Cmaj7, Dm7, Em7, Fmaj7, G7, Am7 and Bm7♭5. Every one of them is made from the notes of the C major scale, so over all of them you could just play C major. Starting that same scale from each chord's root gives you its mode:
- Cmaj7 (I) — C Ionian, the major scale itself
- Dm7 (ii) — D Dorian
- Em7 (iii) — E Phrygian
- Fmaj7 (IV) — F Lydian
- G7 (V) — G Mixolydian
- Am7 (vi) — A Aeolian, the natural minor
- Bm7♭5 (vii) — B Locrian
Same seven notes, different centre. That's why a minor chord gets Dorian when it's a ii and Aeolian when it's the home chord: the scale that fits is the one that matches the key the chord lives in.
The worked example: a ii–V–I
The most common progression in jazz and a lot of pop: Dm7 – G7 – Cmaj7 in C. All three chords come from C major, so C major (or C major pentatonic) carries you through all of it.
To make the changes audible, aim for each chord's 3rd and 7th — the guide tones. They move by tiny steps from chord to chord:
- the C of Dm7 (its 7th) falls to the B of G7 (its 3rd) and stays on B over Cmaj7 (its 7th);
- the F of Dm7 (its 3rd) stays as the F of G7 (its 7th) and falls to the E of Cmaj7 (its 3rd).
Play those two lines slowly over the progression and you'll hear the harmony move with you. Then decorate around them.
When a chord doesn't belong to the key
Songs borrow chords from outside their key all the time. The most common case is a secondary dominant: a major or 7th chord that pulls to another chord of the key a fourth up. In C major, A7 pulling to Dm is one.
Over that A7, C major's C natural clashes with the chord's C#. The fix is a scale built on A that keeps the C#: A Phrygian dominant when it resolves to a minor chord, as here, or A Mixolydian when it resolves to a major one. Or simply aim for the chord tones until you're back in the key.
Let the song tell you
Working this out by hand means knowing the key, every chord, and what each one is doing. easyimprov does that reading for you: upload a track and it shows each chord's degree and function, and the scale to play over it, as the song plays.