Banjo Tuner — Five-String gDGBD and Tenor CGDA

A five-string banjo in open G is tuned g4–D3–G3–B3–D4, with the fifth string’s G an octave above the third string’s G. The fifth string is shorter than the others and sits above the first string in pitch, which is why the tuning is described as re-entrant.

How to use it

1. Start the tuner. Press Start Tuner (Microphone) and allow microphone access. The audio is analysed in your browser; nothing is uploaded.
2. Choose the preset — or check that the page chose it for you. This page opens on the five-string preset, and the selector is visible because the tenor is a different instrument with its own tuning. Pick Banjo (5-String) for open G or Banjo (Tenor) for CGDA before you play a note.
3. Read the cards in string order, not pitch order. The board runs from the 5th string at the top to the 1st at the bottom, because that is how the strings are numbered on a banjo. On the five-string, the first card is the high G4 drone string, which is the highest note on the instrument, not the lowest.
4. Pluck one string cleanly, away from the bridge. A banjo is loud and bright, and a hard attack near the bridge emphasises harmonics the detector has to reject. Pluck with the pad of the thumb or a finger about a third of the way up the string and let the note ring.
5. Mute the other strings. A banjo’s head couples the strings, so an unplayed string rings sympathetically very easily. Rest the side of your picking hand across the strings you are not tuning.
6. Turn the peg toward the note. A needle left of centre means the string is flat; a needle right of centre means it is sharp. Ease the string below a sharp target and come back up to it.
7. Follow the string numbers around the instrument, then check the 5th string again. The five-string’s short drone string is the first one you will see but the last one that settles: because it is short and light, it moves quickly when the neck tension changes as the other strings come up.
8. Use the hear-tone buttons. Each card plays its own reference pitch, which is the quickest way to check the high G against the third string’s G in the octave below.

Tuning order and string tension

• One string at a time, in small steps. Every string you raise adds tension that pulls the neck slightly and shifts the others. Bring each string most of the way, then work around the instrument again rather than trying to finish one string perfectly before moving on.
• Approach from below. If a string is sharp, slacken it below the target and bring it back up. Coming up to pitch seats the string on its peg and holds better, and on a banjo’s light strings the difference is noticeable.
• The fifth string is the one that changes most. It is the shortest and lightest string in the set, and small peg movements move its pitch a long way. Turn its peg in very small increments.
• New strings need a second and third pass. Banjo strings are light gauge and stretch quickly at first. Expect to retune several times in the first playing session.
• A bridge that moves is a tuning change. The bridge on a banjo is held in place by string pressure alone. If you knock it while fitting strings or changing a head, the intonation shifts even though the open strings still read correctly.

Five-string open G

The preset follows Deering’s banjo tuning guide, which gives the standard open G tuning as G, D, G, B, D from the 5th string to the 1st. The cards are listed in that order, so the first card is the 5th string, not the lowest-pitched string.

Card order	String	Note	Frequency (A4 = 440 Hz)
1	5th (short drone)	G4	392.00 Hz
2	4th	D3	146.83 Hz
3	3rd	G3	196.00 Hz
4	2nd	B3	246.94 Hz
5	1st	D4	293.66 Hz

Why the first card is the highest string

Wikipedia’s banjo article describes the fifth string as the same gauge as the first but starting from the fifth fret, “three-quarters the length of the other strings”, which lets it be tuned to a higher open pitch than the full-length strings. Because of that short string, the tuning is re-entrant: “the string pitches do not proceed lowest to highest across the fingerboard. Instead, the fourth string is lowest, then third, second, first, and the fifth string is highest.”

That is the whole reason the cards look out of order. On a guitar the top card would be the lowest string; on a five-string banjo the top card is the short string at the top of the instrument, and the deepest note is the 4th string — the second card.

The drone string

The short string is not just the highest; it is the string the instrument is built around.

• It has two working names. Deering’s blog explains that the fifth string is called the “thumb string” or “drone string” because early clawhammer technique used the thumb to pick it, and Deering’s five-string description says plainly that the short fifth string “is the highest in pitch and used mainly as a drone string”.
• The drone is a rhythm device. Wikipedia describes banjo drone notes as quick notes — typically eighth notes — usually played on the 5th string to fill in around the melody. In clawhammer and frailing, the thumb catches the fifth string after a strum, and the steady high G is a large part of the instrument’s characteristic drive.
• It is rarely fretted. Because it starts at the fifth fret, the short string normally sounds its open G. Players change key by retuning it or by using a fifth-string capo (often a small spike under the string), not by fretting it like the other four.

Tenor and four-string banjo

The tenor is a different instrument with a different tuning, so it gets its own preset in the selector.

String	Note	Frequency (A4 = 440 Hz)
4th	C3	130.81 Hz
3rd	G3	196.00 Hz
2nd	D4	293.66 Hz
1st	A4	440.00 Hz

• Standard tenor tuning is CGDA in fifths. Deering describes it as “the intervals of fifths and exactly the same as viola or mandola”. There is no short string and no re-entrant jump: the tenor’s four strings run lowest to highest in the usual way.
• Irish tenor players use GDAE. Deering notes that many Irish players tune G, D, A, E, an octave below a mandolin, and that this needs heavier strings so the tension stays playable. That tuning is not one of the two presets on this page — if you play Irish tenor, tune the fourth string down to G against the chromatic display, or check the strings against the tenor cards’ C, G, D and A where they correspond.
• Plectrum banjo is a third case. The plectrum banjo is a four-string instrument normally tuned C, G, B, D, and some players use “Chicago” tuning, D, G, B, E. This page’s tenor preset does not cover those notes; use the chromatic tuner at /tools/chromatic-tuner/ for a plectrum tuning.
• Check which four-string you have before you tune. A 19-fret tenor and a 17-fret tenor use the same CGDA tuning, but an Irish tenor set up for GDAE will not reach CGDA comfortably at standard string gauges.

Accuracy and limits

• The re-entrant string is the most common source of confusion. G4 on the fifth string is the highest note on the instrument, and the third string is also a G, an octave lower. If the display says G while you tune the fifth string, check which card is highlighted before you touch the peg — a G3 on the third string is the wrong string, not the wrong octave of the right one.
• There are three D strings within reach of the microphone. The 4th string is D3 and the 1st is D4, and on the five-string the first string’s D4 is only a fourth above the third string’s G3. Pluck with the others muted and compare the reading against the card.
• A banjo rings sympathetically more than a guitar. The light strings and the drum head couple tightly, so an unplayed string can dominate the frame. Mute with the side of the hand and pluck once rather than strumming.
• A plucked note decays quickly. The banjo’s note dies fast, so the reading is only steady for a moment. Pluck again and watch the display settle rather than judging a single frame.
• A loose head changes the reading and the tone. Head tension affects how the instrument responds and how much low end the microphone receives. If the whole instrument sounds dull or the readings are unstable, have the head tension checked.
• Room noise competes with a light-string pluck. The banjo is loud but its individual strings are not; in a band situation, a clip-on tuner that senses the headstock is the more reliable tool.
• If the open string is right but fretted notes are not, check the bridge. A banjo bridge is not fixed. The classic check is to compare the open string against the same string fretted at the 12th fret: if the fretted note is sharp, the bridge needs to move away from the neck, and if it is flat, toward the neck.

Safety

• Bring strings up in small increments. Banjo strings are light gauge and break at the loop end if they are shocked. Turn the peg a little, check the reading, then turn again.
• Never force a stiff peg. If a peg will not turn, the string is usually binding. Ease it free rather than applying force, which is how pegs, strings and headstocks are damaged.
• Do not tune an octave too high. The 1st string target is D4 = 293.66 Hz and the 5th is G4 = 392.00 Hz. Tuning either an octave above its target roughly doubles the tension it is designed for and will break the string.
• Give the fifth string’s peg special care. It is mounted in the side of the neck rather than the peghead, and its short string gives very little warning before it snaps if it is pulled up quickly.
• Old strings will not hold a tune. Strings that break while playing or tuning are usually at the end of their life; replacing the set together is better than replacing one string at a time.
• Stop playing before adjusting anything. Especially on stage or in a crowded room, put the instrument down or hold it safely before reaching for a peg.