There’s nothing more rock than banging out some cool minor key riffs and licks. But what you might not recognize is the fact that there are different types of minor scales that give many remarkable chord progressions.
Let’s begin with all the All-natural Minor. First we take a normal main scale. Let’s utilize C main for simplicity: C D E F G A B C
The all-natural minor is produced from beginning at the 6th scale degree of the main scale. In this case, it’s A. C main and A minor are what we call relative keys, meaning they share this same key signature.
So A minor is A B C D E F G A
If we stack thirds on each of those notes and build chords we receive this:
Am Bdim C Dm Em F G Am
i iidim III iv v VI VII i
Back when the older dead men were nonetheless alive and figuring all of this stuff out, they decided they didn’t that way sound of that minor v chord. It didn’t have the same form of tension-release pull to the i as a V-I does in a main scale. So they changed it and prepared is a main V. E main (changing G to G#) in our case here.
But just like in algebra, what we do to one side we have to do to the other. So if we change the chord we have to change that note in the scale too. Here’s our new scale with the changed note.
A B C D E F G# A
That’s the Harmonic Minor scale. Look at how changing one note changes the chords that can be built:
Am Bdim Caug Dm E F G#dim Am
i iidim IIIaug iv V VI viidim i
Changing just the one note changed the qualities of three chords! And we get some really juicy diminished and augmented chords from this one.
But this scale too had a problem to the old guys’ ears. They didn’t like the sound of the 1 1/2 step move from the 6th to 7th scale degrees. Some historians have said they found it it too “Eastern” sounding.
So they said let’s sharp the 6th scale degree and then it will be smooth at the top like a major scale. Here’s our new scale then:
A B C D E F# G# A
This is called the Melodic Minor scale. BUT there’s a trick. When you go up the scale it sounds fine. Coming back down the scale you get a nasty little surprise when you hit the 3rd scale degree. Everything sounds nice and happy and then it gets sad and depressing in the last 3 notes. The old guys didn’t like that either. So they decided that the sharped 6th and 7th would only be used when the melody is ascending. A descending melody would revert back to the natural minor.
Here’s the Melodic Minor chords:
Am Bm Caug D E F#dim G#dim Am G F Em Dm C Bdim Am
i ii IIIaug IV V vidim viidim i VII VI v iv III iidim i
Look at how many flippin’ chords you have access to there! 13 different chords instead of just the regular 7! That’s a lot of room to play around!
Now for the last one. Melodic Minor is all well and fine when you’re an old dead guy composing on paper and you can see which direction your melody is moving. But let’s enter the jazz age and later where we’re improvising at lighting speeds. The jazz guys decided they didn’t want to have to think about which direction their melodies were moving to decided which part of the natural minor to use.
They decided they could live with that “suprise” when hitting the 3rd on the descending scale. So a Jazz Minor is the Melodic Minor scale with the sharped 6th and 7th in BOTH DIRECTIONS. A small change, but one that lessens the thinking that has to be done while playing.
The best part of this whole thing from a player and songwriter standpoint is that you can mix and match these minor scales as you please. You don’t have to pick just one and stick with it for the whole song. You can jump back and forth and use all the chords and notes available to you.
The best way to learn these is start with the Natural Minor. Learn one position to start. Then, to learn the others, practice just altering the notes that need to be changed. Don’t try and learn it as a whole new pattern. The more you understand about how one pattern morphs into another, the less memorizing you’ll have to do. And you’ll have a better understanding of both the music and the fretboard.