The Nashville Number System is great for figuring out chords on the fly but if you want to work out a chord progression in a minor key it gets a little clumsy.
When we talked about the Nashville Number System earlier in the book we numbered each note of the scale with an Arabic numeral. In a more formal music theory setting we have to use Roman numerals to number each note. This allows us to use upper case numerals for major chords and lower case numerals for minor chords.
For a major scale the first, fourth, fifth and eighth notes of the scale will be major chords marked with upper case numerals. The second, third and sixth notes of the scale will be minor chords marked with lower case numerals. The seventh note is ignored for now.
A C major scale marked out this way will look like this:
I ii iii IV V vi I C D E F G A B C
This winds up exactly the way it did for the Nashville Number System. It changes when you lay out a chord progression from a minor scale.
In a minor scale the first, fourth and eighth notes are marked with lower case numerals to indicate minor chords. The third, sixth and seventh notes are marked with upper case numbers to indicate major chords. The fifth note will be marked as a minor chord with a lower case number in a natural minor scale. In a
harmonic minor scale the fifth note can, in some cases, wind up being played as a major chord. The second note in a minor scale, like the seventh note in a major
scale, is ignored.
An A minor scale marked out this way will look like this:
i III iv v VI VII i A B C D E F G A
What this tells us is that in a chord progression in the key of A minor we can play
Am, C, Dm, Em or E, F and G.
Laying out chord progressions this way will really help when you start to experiment with modes.
Modes
In the last chapter I brought up the interesting fact that your major scale and your natural minor scale are also modes: Ionian (major) and Aeolian (natural minor.)
Modes are a tricky subject because they are talked about quite a bit in old time
music but most people really don’t understand them. I’ve run into more than one fiddle player who got a kick out of confusing beginners at a jam by saying that a song was in C Aeolian mode rather than just saying the song was in A minor. As I said earlier in the book, modes came about in the dark ages. For some reason they were given Greek names making things even more confusing because the
modes we use today are completely different from what the ancient Greeks were
working on.
Ionian mode starts the scale on the root, or first note of the scale. Aeolian mode
starts on the sixth note of the scale. The other modes you will run into fall in between these two.
I should warn you ahead of time that we are only covering seven modes. There are quite a few more but the odds of running into them in a folk music context are pretty slim. If modes or any other aspect of music theory intrigues you, pick up some books on the subject or take some music theory classes at your local community college.
V if the scale is a harmonic minor
130 Let’s take a look at seven modes in the key of C major:
1 2 3 4 5 6 7 8 Ionian/ Major: C D E F G A B C Dorian: D E F G A B C D Phrygian: E F G A B C D E Lydian: F G A B C D E F Mixolydian: G A B C D E F G Aeolian/ Minor: A B C D E F G A Locrian: B C D E F G A B
Ionian mode starts with the first note of the scale giving us a standard C major
scale running from C to C. Dorian mode starts with the second note of the scale giving us a scale with no sharps or flats that runs from D to D.
Phrygian mode starts on the third note of the scale and so on.
There are two ways to look at modes. In one respect we are playing in modes all of the time on the banjo because with only four available strings, we usually wind up using part of a scale.
Sometimes a song will be in a major key but use a modal chord progression. For example, “Little Maggie” goes back and forth from the G to F chords. The song is still in G major but the chord progression gives it a modal feel.
In some cases a melody line is written specifically in a mode. If somebody tells you a song is in C Dorian, you are playing the melody from a scale starting on the second note of the C scale (D.) It’s not really C and it’s not really Am so it can be a little bit confusing.
It gets even crazier when you try to play rhythm for a tune played in a mode. In a
major key we can use the Nashville Number System to play the 1-4-5 chords. In
a mode things start to change because the whole layout and sound of the scale has changed.
It gets so confusing that some people believe that modal tunes were never meant to have any accompaniment. That sounds like it might be a reasonable idea until you listen around and find out that rock songs like “The White Room” or “Sweet
Home Alabama” were written in modes.
Let’s say the song you want to back up is in C Dorian mode. That means you are playing the notes of the C major scale from D to D. When we laid out chord progressions using Roman numerals to mark what chords would be played major or minor in a C scale we marked the D or “2” note as being a minor chord.
I ii iii IV V vi I C D E F G A B C
Uppercase numerals indicate a major chord and lower case numerals indicate a minor chord.
So if C Dorian is starting on the D note we know right away that we stand a good chance that a Dm chord is going to fall into place somewhere in the tune. Once you know that you can try other chords used in Dm and figure out what will or won’t work for the song. Keep in mind that you are not playing the key of Dm but this trick will at least give you a head start in figuring out the chord progression by ear. It’s not an exact science but if you give yourself time to develop your musical ear it all starts to make sense.