This tune is in A dorian. That means that available chords are A minor, B minor, C major, D major, E minor, F# diminished and G major. If you’d like to fully understand the modes and why certain chords fit certain keys then you’ll need my first book Backing Guitar Techniques for Traditional Celtic Music, or an Amazing Mode Wheel from Finale Guitar.
In bar two I have used a G major chord, which is chord VII within the key of A dorian. This fits well because the melody notes are “B A B D G – A G”. The notes of a G chord are G, B and D so this chord is an obvious fit for this bar.
Chord V appears on every seventh foot tap (or fourth bar) as usual. In most tunes I would resolve to chord I at the end of the first play through the A part. In this particular one I prefer not to, until the end of the repeat of the A part (either is fine).
The B part’s harmonic structure is basically the same as the A part’s, so I have used the same chords.
In this version I have replaced the E minor in bar four with its related major, G major. In any mode other than ionian, you can replace the minor V chord with its related major chord. A minor chord’s related major is always the one whose root note is two notes above it in the key scale- in this case E (minor) – F# – G (major). As well as this substitution, I have added an approach chord to the G- I approach it from a semitone below.
As G is chord VII in the mode of A dorian, you might expect me to approach it using F# diminished, the chord in the key whose root is one below G. However folky guitarists tend to avoid diminished chords as they sound rather unpleasant. Instead I use the first inversion of a D major chord, which in practical terms is just a D major chord with your thumb looped round the back to fret an F# on the second fret of the low E string. This substitution works because D major contains the notes D, F# and A, and F# diminished contains F#, A and C- the two chords share two notes. In any key you can avoid the diminished chord by using the first inversion of the chord whose root is two notes lower in the scale, eg F# dim becomes D/F#, C# dim. becomes A/C#, B dim. becomes G/B etc.
In bar seven I have replaced A minor with its related major, C.
In the B part, inverting the G chord in bar two creates a nice walking bassline from A up to its related major, C. A G chord contains the notes G, B and D, so its first inversion has the B at the bottom pitch within the chord.
When we begin to introduce tetrads into the dorian mode, the available options are I minor 7, II minor 7, III major 7, IV (dominant) 7, V minor 7, VI ½ diminished and VII (dominant) VII. In this case, our options are A minor 7, B minor 7, C major 7, D (dominant) 7, E minor 7, F# ½ diminished and G (dominant) VII. Notice that as dorian is the second mode, these are the same jazzy options which would be available in the key of G ionian, with the addition that in the dorian mode chord VII is also a dominant 7 chord.
If you recall that you can play chord I, chord IV or any chord related to either of those two in a chord I section, you should have no trouble decoding why the first line works well.
In bar seven of the A part, I have “borrowed” an F major chord, as if we were playing in A aeolian instead of A dorian. In Irish music in minor keys, the sixth note of the scale (in this case F) is rarely used in the melody. This means that you can often use chords from either mode- you only have to stick rigidly to the “right” chords for the dorian mode in bars which contain the sixth note. As this bar contains no F#s in the melody, I have used the darker sounding F major chord. I then use D/F# (a substitute for F# diminished) to create a chromatic link up to a G (chord VII)- F – F# – G.
This chromatic link is continued by using G# diminished to link G back to A via G#. You can always use a diminished chord whose root note is on the semitone between two other chords to create an ascending chromatic link. If you want to create descending chromatic links then use a dominant 7 chord instead.
In the B part I switch to shapes which are higher up the neck, as shown below. I invert the G chord in the second bar, to set up an A – B – C bassline between the first three bars. C major add 13 is a valid substitute for C major, because adding any extra notes from within the key scale to a chord will just give you a jazzier version of the same. C major add 13 is a C chord with an A note added so this sounds great in the key of A dorian.
Remember I said that you could borrow chords from the aeolian mode in a dorian tune if the melody didn’t contain the sixth note in the bar in question? Well, bar five of the B part actually DOES contain an F#, but it’s right at the end so I think the guitarist can get away with a dark, moody F major 7 chord there. I like to play the first four bars of the A part using light tinkly chords a way up the neck, and for contrast play the second half low down using the dark brooding chords of the aeolian mode.
Finishing on an Am13 gives the tune a cool, gypsy jazz style flourish!
A part jazzy chord shapes
B part jazzy chord shapes
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