An instrument that began as a retuning
The Irish bouzouki is tuned G2–D3–A3–D4 — GDAD — in four courses of two, and every course is a unison. Eight strings, four pitches, no octave pairs anywhere.
It exists because of one decision. In the mid-1960s Johnny Moynihan took a Greek tetrachordo bouzouki, tuned C3–F3–A3–D4, and retuned its two lower courses to G and D for Irish traditional music. The A and D courses on top stayed exactly where they were. That tuning caught on, instruments started being built for it, and within a couple of decades the Irish bouzouki was its own instrument — flatter backed, longer scaled, and without the octave courses its parent carries.
The third tab is the Greek tuning this instrument came from — play it against the first and you can hear exactly which two courses moved and which two stayed.
Why GDAD, and what it is for
GDAD is an accompanist’s tuning, and every part of it is doing a job.
The two D courses an octave apart give you a drone that sits under everything — play a shape anywhere and those Ds tend to ring through it, which is precisely the sound Irish backing wants. Between them the G and A let you build the modal two-finger shapes that accompaniment lives on: chords that decline to commit to major or minor, matching tunes that are themselves modal.
The alternative, GDAE, is a fifths tuning an octave below a mandolin. It is better for playing melody, because fiddle and mandolin fingering transfers unchanged — which is why so many players who came from those instruments use it. Neither is more correct; they are tuned for different jobs.
Tuning routine
- Damp one string of the course you are working on. A fingertip on its partner is enough. Two strings a few cents apart produce a wavering tone that a detector will chase rather than name.
- Start with the 2nd course, A3. It is an octave below concert A and the easiest reading on the instrument, which makes it a good anchor.
- Then the 1st course, D4, and the 3rd course, D3. Do these consecutively and check the octave between them while it is fresh — this is the pair that goes wrong.
- Then the 4th course, G2. The lowest note on the instrument; give it a moment to settle before reading.
- Match every pair by ear before moving on. Two strings can both read centred and still beat audibly. Play the pair and adjust until the wavering flattens out — that, rather than the needle, is when a course is finished.
- Go round twice. Eight strings at tension move a lightly built top as you work, and the first course drifts while you set the last.
Bouzouki, octave mandolin, cittern
The names in this corner of the instrument world are used loosely, and scale length is what actually separates them. An octave mandolin is GDAE on a scale around 20 to 23 inches. An Irish bouzouki is typically 24 to 26 inches and usually GDAD. A cittern generally has five courses rather than four.
The overlap is real: tune a bouzouki to GDAE and you have something close to a long-scale octave mandolin. The longer scale is what gives the bouzouki its deeper voice and longer sustain, and that is the property that makes it an accompaniment instrument rather than a melody one.
What the needle can and cannot settle
Four pitches is a quick job; eight strings is not. The dial gets each string into position and then stops being useful, because what you are really tuning is four pairs — and a pair is judged by whether it stops beating, which is a question about two strings together rather than either one alone.
There is also the drone to consider. In GDAD you are effectively playing over a sustained D much of the time, and the intervals that lock against a drone are not always the ones equal temperament nominates — this is the same logic that governs pipes and fiddle in the same repertoire. Our guide to cents covers how far apart the two answers sit. For the parent instrument, see the Greek bouzouki tuner; for the same fifths tuning an octave up, the mandolin tuner.
Frequently asked questions
What is standard tuning for an Irish bouzouki?
GDAD — G2, D3, A3, D4 — in four courses of two strings, every course a unison. That is the tuning that defines the instrument, and it exists because Johnny Moynihan retuned a Greek bouzouki to it in the mid-1960s to suit Irish traditional music. The alternative worth knowing is GDAE, which is a fifths tuning an octave below a mandolin and suits players arriving from fiddle or mandolin, since the fingering patterns transfer directly. Both are standard; GDAD is more common for accompaniment because of the drone it produces.
Why GDAD rather than a tuning in fifths?
Because of what it does behind a tune. The two D courses an octave apart give you a built-in drone, and the G and A between them let you play the modal chord shapes Irish accompaniment lives on — moving a simple two-finger shape around without ever quite committing to major or minor. That ambiguity suits tunes that are themselves modal. A fifths tuning like GDAE is better for playing melody, which is exactly why players who came from mandolin often prefer it.
Are any courses tuned in octaves?
Not in standard GDAD — all four courses are unisons, two strings at the same pitch. That is one of the clearest differences from the Greek bouzouki, whose two lower courses are octave pairs. Some players do string the G course, and occasionally the D, in octaves to add brightness in the bass, and it is a legitimate choice rather than a mistake. But it is a modification, so if you buy an instrument second-hand it is worth checking each string of the lower courses separately before assuming.
Why do I keep putting a string an octave out?
Because the tuning has two D courses an octave apart, and an octave error on either of them sounds almost plausible. Tune the 1st course down to D3 and it sits in unison with the 3rd course; take the 3rd up to D4 and it doubles the 1st. Both mistakes produce something that still sounds like a chord, so the ear does not immediately object — the instrument just goes oddly thin or oddly muddy. Watch the octave digit on both D courses and check the interval between them, which should be a clear octave.
Is an Irish bouzouki the same as an octave mandolin?
They overlap enough that the names are used loosely, and the practical difference is scale length. An octave mandolin is tuned GDAE, an octave below a mandolin, on a scale usually around 20 to 23 inches. An Irish bouzouki is typically longer, around 24 to 26 inches, and usually tuned GDAD. Tune a bouzouki to GDAE and you have something very close to a long-scale octave mandolin; the longer scale gives more sustain and a deeper voice, which is what suits it to accompaniment.