GDAE or CGDA? Which tuning for Irish tenor banjo
A tenor banjo bought second hand is almost always in CGDA, and almost every Irish player retunes it to GDAE. Here is why, what it does to the strings, and how to make the change without breaking anything.
- Short answer
- GDAE, unless you are playing jazz or trad jazz
- CGDA means
- The four strings tuned C, G, D, A. The original tenor banjo tuning, used for jazz
- GDAE means
- The four strings tuned G, D, A, E. Fiddle and mandolin tuning, and what Irish music uses
- Who made GDAE the standard
- Barney McKenna of The Dubliners, in the 1960s
- The risk when you retune
- GDAE pulls every string higher than CGDA, so old strings can snap
- What you need to change over
- A string set sold for GDAE, matched to your scale length
What are GDAE and CGDA tuning?
CGDA is the original tenor banjo tuning and it is what the instrument was built for. It runs in fifths from the C below middle C, and it is what you will find on a banjo bought from a general music shop or inherited from someone who played in a dance band.
GDAE is a fifth higher on every string, and it is the tuning of a fiddle and a mandolin. That is the entire reason Irish players use it. The tunes sit under your fingers exactly as fiddle players finger them, and the whole written tradition of Irish music becomes directly usable.
The switch is usually credited to Barney McKenna of The Dubliners. Before it, the tenor banjo in Irish music was largely a rhythm instrument. After it, it became a melody instrument, and everything this site does depends on that change.
| String | CGDA | GDAE | Change |
|---|---|---|---|
| 4th (lowest) | C3 | G2 | down a fourth |
| 3rd | G3 | D3 | down a fourth |
| 2nd | D4 | A3 | down a fourth |
| 1st (highest) | A4 | E4 | down a fourth |
What goes wrong when you retune to GDAE?
Every string ends up at higher tension, and old strings can snap. Read the table again and it looks like the pitches go down, which sounds harmless. In practice the change is usually described the other way round, because players keep the same physical string in the same slot and move its pitch up: the C string becomes G, the G becomes D, the D becomes A and the A becomes E.
That is the version that matters for your instrument, because it means every string is being asked to hold more tension than it was made for. Standard CGDA strings taken up to GDAE will feel tight and the top string may well snap.
The fix is simple and it is not optional: fit a set sold for GDAE at your scale length. Come up to pitch over a few minutes rather than all at once, and if the nut was cut for heavier strings it may need easing slightly.
Which strings do you need for GDAE?
A set sold specifically for GDAE, matched to your scale length. That is the whole answer, and it never gets given straight on forums because people argue about 17 frets against 19 frets when the number that matters is the distance from nut to bridge.
A shorter scale needs heavier strings to reach the same pitch at a playable tension. A 17-fret banjo with a 19 inch scale wants a noticeably heavier set than a 23 inch instrument tuned to exactly the same notes. Measure from the nut to the bridge and buy for that.
There is a full table of starting gauges by scale length on the tuning page, along with the exact frequency of each string.
When should you keep CGDA instead?
If you are playing trad jazz, dance band material, or anything from the tenor banjo's original repertoire, stay in CGDA. That is what the instrument and the entire body of written music for it were built around.
If you are playing Irish traditional music, GDAE, without hesitation. Every tutor, every tab book, every course and every session assumes it.
Why does written banjo music sound an octave lower?
Because the tenor banjo is a transposing instrument: it is written at fiddle pitch and sounds an octave below it. Worth knowing before you compare notes with a fiddle player. An Irish tenor banjo sounds an octave below a fiddle but is written at fiddle pitch. It is a transposing instrument.
That is why the tab on this site, and in every published Irish banjo book, is worked out from the written pitch rather than the sounding one. It is also the single most common bug in automatic tab generators, which produce fingerings an octave out and then insist they are correct.
Questions about GDAE and CGDA
The things people ask before they commit to an answer.
GDAE for Irish traditional music, and CGDA for jazz or dance band playing. GDAE matches fiddle and mandolin, so the tunes fall under your fingers the way every Irish tutor and tab book assumes.
Not the instrument, but possibly the strings. Every string is being asked to hold more tension than a CGDA set was made for, so fit a set sold for GDAE at your scale length and bring it up to pitch over a few minutes rather than all at once.
A set sold for GDAE, chosen by scale length rather than fret count. Measure nut to bridge. A shorter scale needs heavier strings to reach the same pitch at a playable tension, which is why the same set feels wrong on two different banjos.
Because it is fiddle tuning. Irish traditional music is a fiddle-centred tradition, and matching the fiddle means the fingering, the tunes and the whole written repertoire transfer directly. The change is usually credited to Barney McKenna of The Dubliners.
The note names are the same, GDAE, and the fingering is identical, so tab written for one works on the other. The pitch differs: a tenor banjo sounds an octave below a mandolin.
Tune the A string to a reference, then tune the rest in fifths. Fret the D at the seventh and it should match the open A, fret the G at the seventh to match the open D, fret the A at the seventh to match the open E. Fifths are harder to hear than octaves, so a clip-on tuner is worth the money early on.
Keep reading
The 20 tunes you'll actually hear at a session
Every session has its own repertoire, but a core of tunes turns up night after night, in Ireland and everywhere the music travels. Here are twenty of them, grouped by type, with free GDAE tab for each. Ten of these played steadily is enough to take part.
Read the guideIs the Irish tenor banjo hard to learn?
Easier than the fiddle, harder than it looks on YouTube. The notes come quickly and the right hand takes years. Here is an honest account of what is actually difficult, what is easier than people expect, and how long it takes to be useful at a session.
Read the guideHow fast should Irish tunes be played?
Almost every published tempo for Irish music is unusable, because the number is given without saying what one beat is. A reel and a hornpipe both listed at 113 are running at 56.5 and 28.3 bars per minute. Here are the figures with their units named.