Minor triad arpeggios on guitar
Root, ♭3 and 5th — the minor chord tones, and how one changed note flips a triad from major to minor.
- Notes
- A · C · E
- Formula
- 1 · ♭3 · 5
- Notes in the scale
- 3
A minor triad is the major triad with the 3rd flattened by one fret. Root, ♭3, 5. That single semitone is the entire difference between the two, which is worth feeling under the fingers rather than only knowing as a fact.
As with major triads, learn them on string sets so you can find the shape without shifting position. And practise moving between the major and minor triad on the same root — one finger moves, the sound changes completely.
Over a minor key vamp, these three notes are the safest places to land, and the ♭3 in particular is the note that confirms to a listener which key they are in.
Where it sits on the neck
On the top three strings in A the first shape is a straight barre: the 5th fret of the G, B and high e strings gives you C, E and A. That is an A minor triad played with one finger, and it sits inside box 1 — which is not a coincidence, because box 1 was built around it.
The other two on the same string set are E at the 9th fret of the G, A at the 10th of the B and C at the 8th of the high e; and then A at the 14th, C at the 13th and E at the 12th.
Now compare the barre at the 5th fret with the major triad. Move the G string alone from the 5th fret to the 6th and A minor becomes A major. One finger, one fret — and it is the same fret the blues bend comes from, which is why the bend sounds like a chord changing rather than a note moving.
- Root on the A string — the open strings to the 3rd fret.
- Root on the G string — the 2nd fret to the 5th.
- Root on the low E string — the 5th fret to the 8th.
- Root on the D string — the 7th fret to the 10th.
- Root on the B string — the 10th fret to the 13th.
What to play it over
Am and Am7, and the i chord of any minor progression. Over the Am, G and F vamp it is safe on the Am, safe on the F — an F chord is F, A and C, so it shares two of the three — and not safe on the G at all. G, B and D has nothing whatever in common with A, C and E.
That is worth testing rather than reading. Hold an A minor triad through the G chord and every note you are playing is a non-chord tone. It floats, it sounds deliberate if you meant it, and it sounds like you lost your place if you did not.
The common mistake
Assuming an arpeggio is safe because the key is minor. A scale belongs to a key; a triad belongs to a chord, and the moment the chord moves the triad stops being the set of safe notes and becomes a set of tensions. That is the whole reason to learn arpeggios in the first place — they follow the harmony where a scale merely tolerates it. If you are going to play chord tones, you have to know which chord is sounding, and if you do not know, play the scale.