Two different tunings share one name
A squareneck resonator is tuned G–B–D–G–B–D — G2, B2, D3, G3, B3, D4. It is called open G high bass, and the second half of that name is the part that matters, because there is another open G and it is not this one.
A six-string guitar gets to open G by dropping strings: D–G–D–G–B–D, with the 6th taken down from E to D. A resonator gets there by raising them: the 6th goes up from E to G and the 5th from A to B. The top four strings are identical on both instruments; the bottom two are a fourth apart.
Which means a guitar open-G chart will put your bottom string in the wrong place, and a guitar open-G string set — gauged for a 6th string sitting at D — will be slack and rattly at G. It is the most common resonator mistake and it has nothing to do with the tuner.
Play the two tabs one after the other. From the 4th string up they are the same instrument; the bottom two strings are where a resonator and a guitar part company.
Why the bottom two strings went up instead of down
The choice follows from how the instrument is played. A squareneck is laid flat and played entirely with a bar — no fretting, ever — so nothing is ever gripped and nothing is ever bent. With a full six-string chord available under one straight bar, the useful thing is to have the chord tightly voiced, not spread across a wide bass range.
Raising the bottom two strings pulls the whole voicing together into two neat octaves of the same triad — G, B, D, G, B, D — so a bar anywhere gives you a compact major chord and the strings all speak at similar volume. Dropping the 6th to D, the guitar solution, gives you a low root for fingerpicking instead, which is what a guitarist wants and a bar player does not.
Tuning routine
- Confirm which open G you are aiming at before touching a peg. Look at the 6th string: on a resonator it should read G2, 98.00 Hz. If it reads D2 at 73.42, you are looking at guitar open G.
- Tune from the 6th string upward, watching the octave digit. This tuning contains two Gs, two Bs and two Ds, so the letter alone is not enough to tell you where you are.
- Check the octave pairs by ear. 6th against 3rd (both G), 5th against 2nd (both B), 4th against 1st (both D). Each pair should lock into one note in two registers.
- Strum all six open and judge the chord. On an open-tuned instrument this is the real test — six centred readings can still add up to a chord that sounds sour, because a chord is heard as intervals rather than as six separate notes.
- Then place the bar over a marker line and play the same chord. Over the line, not behind it. If the chord goes out here but was fine open, the variable is your bar hand.
Squareneck and round-neck
The two builds ask different things of a tuning. A squareneck has a very high nut, is played flat on the lap, and cannot be fretted at all — open G high bass is its home and bluegrass Dobro playing lives there. A round-neck resonator has normal action, can be fretted like a guitar or played bottleneck, and is often kept in standard tuning or open D or open G depending on the player.
If you have a round-neck and want to play both ways, remember that high-bass G asks the 6th string to sit a minor third above its usual pitch — use a set intended for the tuning rather than raising a standard set and hoping.
What the needle can and cannot settle
The dial gets six open strings right, and on a barred instrument that is most of what it can do. Everything above the nut is your hand: no frets means no error built in, and no help either.
There is also a temperament question that arrives with any open tuning. The open strings spell a major triad, and equal temperament’s major third — the B in this case — sits about 14 cents above where the interval locks acoustically. Strum a resonator open and that third is the note that rings a shade bright. It is not out of tune; it is the compromise that lets one instrument play in every key. Our guide to cents explains why the two answers differ. For the same bar technique on a different instrument, see the lap steel tuner; for the same open G on three strings, the cigar box guitar.
Frequently asked questions
Is resonator open G the same as guitar open G?
No, and this is the single most common source of confusion. A six-string guitar reaches open G by dropping strings down: D–G–D–G–B–D, with the 6th string lowered from E to D. A squareneck resonator raises its 6th instead: G–B–D–G–B–D, which is called high bass. Same chord name, different bottom two strings, and a completely different string set — a guitar open-G set has a 6th gauged for D and will sit slack and rattly at G. If a chart says open G, check which G it means before you turn anything.
Can I put a resonator tuning on a normal guitar?
You can play GBDGBD on a round-neck guitar and plenty of blues players do, but the two instruments are different tools. A squareneck Dobro has a very high nut, is played flat on the lap with a bar and never fretted, and is strung heavier to suit that. A round-neck resonator has normal action and can be fretted or played bottleneck. Putting high-bass G on a standard guitar means raising the 6th string a minor third above its usual pitch, so use a set intended for the tuning rather than a standard one.
Why do my chords sound out when every open string is in tune?
Because a bar does not care about your tuner. There are no frets in play on a squareneck — the bar stops the strings wherever you hold it, so pitch is continuous and entirely yours. The fret markers are lines to place the centre of the bar over, not wires to finger behind, and a bar held a few millimetres back plays flat across all six strings at once. A tilted bar is worse still: it puts each string at a slightly different point, which is a chord out of tune with itself.
Do resonators go out of tune faster than other guitars?
They move for a specific mechanical reason: the bridge sits on a spun aluminium cone rather than directly on a wooden top. That cone is a moving part, and it responds to string tension, humidity and temperature more readily than a solid top does. Heavy squareneck strings under open G put considerable load on it. In practice that means a resonator is worth re-checking after it has been out of its case for a while, and a cone that has shifted or a loose coverplate screw will read as a tuning problem when it is really a hardware one.
What string gauges does a squareneck need?
Heavier than a standard acoustic set, because the tuning and the technique both demand it. Squareneck players typically use sets built specifically for open G high bass, often running from around .016 at the top to .056 at the bottom. The reasons are that the raised 6th string needs mass to sound G properly at that pitch, and that a bar needs tension under it to produce clean sustain rather than rattle. Fitting a light acoustic set to a squareneck is a common mistake and produces exactly the buzzy, weak tone people then blame on the cone.