Minor keys are way more complicated than major keys. But the effort is worth it; all that complexity gives a richer array of expressive possibility.
The best place to start with minor keys, paradoxically, is with the major scale modes. The pitches in C major are the same as the ones in A natural minor. If you think of A as home base rather than C, you get a bunch of useful chords and scales.
A natural minor produces chords the same way that C major does. Pick a scale tone, then go around the circle clockwise playing every other note. Here are all seven chords you get from A natural minor:
Am7: A C E G (i) Bm7(b5): B D F A (ii) Cmaj7: C E G B (III) Dm7: D F A C (iv) Em7: E G B D (v) Fmaj7: F A C E (bVI) G7: G B D F (bVII)
These chords all sound good together, in any order. But there’s one very important chord missing that you might expect from looking at real-world minor key usage: E7. To derive it, you’ll need a new scale, one that replaces G with the leading tone G#.
Harmonic minor uses a natural seventh, which in A minor is G#. The scale is called harmonic minor because of the satisfying chords it produces.
Hear harmonic minor at work in “Dido’s Lament” by Henry Purcell, sung here by Jessye Norman. On the line, “When I am laid, laid in earth” the word “earth” lands on the natural seventh that defines the sound of harmonic minor. Listen at 0:28.
The i chord from A harmonic minor is the exotic and mysterious Am(maj7) chord.
A C E G#
This chord is great for a feeling of anxiety, like in Bernard Herrmann’s score for Vertigo.
The V chord in A harmonic minor is E7. It has a tritone between G# and D that creates a feeling of tension and suspense.
E G# B D
If you add another note to the V chord, you get F, the flat ninth. E7(b9) strongly establishes the key of A minor, even if you never hear the A minor chord itself.
E G# B D F
E7(b9) has a diminished chord feel to it. This isn’t surprising — if you ignore the E, you’re left with a G# diminished chord (also B, D or F diminished.) Cascading diminished chords over E7(b9) is a great way to get that Dracula feeling. Hear a classic example in Bach’s Toccata and Fugue in D minor — listen at 0:27.
Extending E7(b9) further to the eleventh and thirteenth gives you an entire F major triad. Playing an F chord with E in the bass is a very hip way to dress up your E7 chord. You can get the same effect by playing D minor over E.
E G# B D F A C
E7(b9) goes with a great scale, too. It’s variously known as Phrygian dominant, Ahava Raba, Freygish mode, or more informally, the Jewish scale. It’s great for middle eastern music, and its cousins flamenco and klezmer.
E F G# A B C D
The third G# makes this scale major, but the F, C and D all make the scale feel minor. The tension between the major and minor feel gives this scale its emotional richness. Here’s Naftule Brandwein playing Freygish mode:
You can get some other valuable minor key chords from the Dorian mode — in A minor, use the pitches from the G major scale.
Here are the chords you get from A Dorian:
Am7: A C E G (i) Bm7: B D F# A (ii) Cmaj7: C E G B (III) D7: D F# A C (IV) Em7: E G B D (v) F#m7(b5): F# A C E (vi) Gmaj7: G B D F# (bVII)
The D7 chord in particular is an important one. Alternating between Am and D7 gives a cool, creamy feel that’s a cornerstone of funk, soul and R&B. It’s also used a lot in Latin music, as in Santana’s version of “Oye Como Va” by Tito Puente:
Putting it all together
Here are the most widely used chords derived from A natural minor, harmonic minor and Dorian side by side:
Natural Harmonic Dorian I Am7 Am(maj7) Am7 II Bm7(b5) Bdim7 Bm7 III Cmaj7 Caug Cmaj7 IV Dm7 Dm7 D7 V Em7 E7(b9) Em7 bVI Fmaj7 Fmaj7 -- VI -- -- F#m7(b5) bVII Gmaj7 -- G7 VII -- G#dim7 --
By mixing and matching from the three scales, you can get a wide range of feeling. It can be confusing to keep track of which scale goes with which chord, especially because there’s so much overlap between them. The best thing to do is to master the three different scales in isolation, and then your ear will help you determine which one sounds best in each situation.
This post doesn’t begin to include all the of the possible minor-key chords and scales. Blues scale could be considered a minor scale, and it sounds terrific over all the chords mentioned here. There’s also the supremely weird melodic minor scale, which will be getting a full post of its own. The main thing is not to get too bogged down in all the music theory. Get in there, start throwing chords together, and let your ear be your guide as to what works and what doesn’t.