Dobro / Resonator tuner – Open G (GBDGBD)
G-B-D-G-B-D · Open
Press “Start tuner” – the browser will ask for microphone access. Sound is analysed on this device and never uploaded.
This free online tuner listens through your microphone and shows how close each string of your Dobro / Resonator is to Open G (GBDGBD) tuning (G-B-D-G-B-D). Play a string, watch the needle, and turn the peg until the meter glows green. If you prefer tuning by ear, tap any string card to hear its reference tone.
About Open G (GBDGBD) tuning
Open G (GBDGBD) is the reference tuning for the Dobro / Resonator – the pitch the instrument normally ships at, and the starting point every other tuning on this page is measured from.
Played open, the strings sound G-B-D-G-B-D – from G2 at the bottom to D4 at the top, a span of 1 octave and 7 semitones. Step by step across the neck the intervals are a major third, a minor third, a fourth, a major third, a minor third, and that is what decides how chord shapes fall under the hand.
Strummed open, with nothing fretted, the strings spell G. That is what makes a tuning like this useful for slide playing and drones – a full chord is one straight barre away at any fret. See G shapes in this tuning →
Open G is the standard tuning of the resonator guitar played lap style. The instrument is not fretted at all – a steel bar slides over the strings – so the tuning has to supply the harmony, and an open major chord is what makes that possible.
This is the sound of bluegrass dobro: Josh Graves brought it into Flatt and Scruggs' band in the 1950s and made the resonator a lead instrument. The action is set deliberately high, so a dobro in this tuning cannot be played as an ordinary guitar.
History
Dobro / Resonator
Steel-guitar playing – sliding a hard bar along strings raised off the fretboard – is credited to the Hawaiian Joseph Kekuku around 1885, and by the 1920s Hawaiian music was a national craze in the United States. Players needed more volume than a wooden guitar could deliver, and in the late 1920s the Slovak-American Dopyera brothers answered with metal resonator cones: John Dopyera co-founded the National String Instrument Corporation in 1927, then left with his brothers to start the Dobro Manufacturing Company in 1928.
“Dobro” is a contraction of Dopyera Brothers and also means “good” in Slovak. Their single inverted cone gave a sweeter, more nasal sound than National's designs, and the square-neck Dobro, played flat on the lap, became a bluegrass instrument when Josh Graves joined Flatt & Scruggs in the 1950s. Jerry Douglas carried it into modern acoustic music; the brand name Dobro is now owned by Gibson, but it is used loosely for any wooden-bodied resonator guitar.
Where the Open G (GBDGBD) tuning comes from
G-B-D-G-B-D, “high G” tuning, became the standard for the square-neck resonator guitar in bluegrass. It was popularised by Josh Graves when he joined Flatt & Scruggs in the 1950s and established by later players such as Mike Auldridge and Jerry Douglas. It evolved from the Hawaiian steel-guitar tunings of the 1920s and 30s.
Other Dobro / Resonator tunings
Chords for this tuning
How do I tune my Dobro / Resonator to Open G (GBDGBD)?
Allow microphone access, pluck a string, and the tuner will detect it automatically. The needle shows whether the string is flat or sharp – adjust until the reading is within ±5 cents (G-B-D-G-B-D).
Which notes are used in Open G (GBDGBD) tuning?
Open G (GBDGBD) tuning for Dobro / Resonator uses the notes G-B-D-G-B-D, listed from the lowest string to the highest.
Can I tune without a microphone?
Yes. Every string card plays a reference tone – tap it and match your string to the sound by ear.