What chords do I need for Irish music on octave mandola?

Eight cover most of it: G, D, A, C, Em, Am, Bm, Dm. Irish trad sits mainly in D and G, plus their modal relatives, so a small vocabulary goes a long way.

How do I read a GDAE chord diagram?

The four vertical lines are the strings, low G on the left through to high E on the right, as you see them looking down at the instrument. The thick bar at the top is the nut. A filled dot is a finger, a hollow circle above the nut means play that string open, and a cross means do not sound that string.

Why do guitar chord shapes not work on octave mandola?

Guitar is tuned in fourths and GDAE is tuned in fifths, so nothing transfers. The upside is that a chord shape keeps the same pattern everywhere on the neck, so there are far fewer shapes to learn and no barre chord for every key.

What is a dorian tune and why does it matter for chords?

Most Irish tunes are modal rather than plainly major or minor. A tune in E dorian uses the notes of D major but centres on E, so it wants Em, D and G behind it rather than the classical minor harmony an ear trained on pop music reaches for. Putting a B major behind an E dorian tune is the most common backing mistake there is.

Octave mandola · GDAE tuning

Octave mandola chords

Every chord Irish traditional music actually uses. These shapes are worked out from the tuning itself, so the notes under each diagram are what the chord genuinely sounds. The same shapes work on tenor banjo, mandolin and octave mandola, because all three are tuned GDAE.

The eight that cover most tunes

Irish trad lives in a handful of keys. Learn these and you can back most of a session.

0 0 2 3

2 0 0 2

2 2 4 0

0 2 3 0

0 2 2 0

2 2 3 0

4 0 2 2

2 0 0 1

Sevenths and suspensions

Used sparingly. A seventh at the end of a part pulls the tune back round to the top.

0 0 2 1

2 0 3 2

2 2 4 3

0 0 2 0

2 2 3 3

0 0 0 3

Which chords go with which key

Irish tunes are modal. Match the mode and two or three chords will carry a whole tune. Do not over-chord, and do not impose classical minor harmony on a dorian tune.

Key or mode	Core chords	Turnarounds
G major	G, C, Em	Am, D, D7
D major	D, G, Bm	Em, A7
E dorian	Em, D, G	C, Bm, A
A dorian	Am, G, C	F, Em, D
D mixolydian	D, C, Am	Bm
A mixolydian	A, G, Em	D
D minor	Dm, Am, C	Bb, F

FAQ

Questions

Eight cover most of it: G, D, A, C, Em, Am, Bm, Dm. Irish trad sits mainly in D and G, plus their modal relatives, so a small vocabulary goes a long way.
The four vertical lines are the strings, low G on the left through to high E on the right, as you see them looking down at the instrument. The thick bar at the top is the nut. A filled dot is a finger, a hollow circle above the nut means play that string open, and a cross means do not sound that string.
Guitar is tuned in fourths and GDAE is tuned in fifths, so nothing transfers. The upside is that a chord shape keeps the same pattern everywhere on the neck, so there are far fewer shapes to learn and no barre chord for every key.
Most Irish tunes are modal rather than plainly major or minor. A tune in E dorian uses the notes of D major but centres on E, so it wants Em, D and G behind it rather than the classical minor harmony an ear trained on pop music reaches for. Putting a B major behind an E dorian tune is the most common backing mistake there is.