Three tunings, and you have to pick one first
A tenor guitar has four strings and a short scale — 21 to 23 inches against a guitar’s 25.5 — and it arrived in the 1920s so that tenor banjo players could move to a guitar body without relearning the neck. That origin is why its standard tuning is C–G–D–A, in fifths, and why its nearest relatives are the mandola and the viola rather than the six-string it is named after.
Unlike a baritone’s B, A and C standard — which are one tuning transposed three ways — a tenor guitar’s three tunings are genuinely different instruments in the same body. They do not share an interval pattern, they do not share a repertoire, and they do not share string gauges. Work out which one you are on before you turn anything.
Highlighted strings differ from standard CGDA. Tap any string to hear its reference pitch.
Which tuning is on your instrument?
Secondhand tenor guitars almost never come with a note saying how they were strung, and the three sets are far enough apart that guessing wrong costs you a string or a neck. The gauges are the honest answer:
| Tuning | Notes | Typical low string | Played by |
|---|---|---|---|
| Standard | C3–G3–D4–A4 | .036 | Tenor banjo players, jazz and old-time |
| Irish / Celtic | G2–D3–A3–E4 | .048 | Irish trad — melody from fiddle fingerings |
| Chicago | D3–G3–B3–E4 | .032 | Guitarists doubling on tenor |
Tuning routine
- Start with the 1st string. In CGDA that is A4 — concert A, 440 Hz — which is the one pitch on the instrument you can check against almost anything else in the room. Centre the needle there first and work down.
- Tune down in fifths. D4, then G3, then C3. Each one is a fifth below the last, and a fifth is the interval that is easiest to hear going out: as you approach, the beating between the two open strings slows and then stops.
- Check the outer pair. C3 against A4 is two octaves and a major sixth — too wide to judge by ear, so read it off the dial rather than trusting the interval.
- Go round twice. A short scale at low tension means each string you move shifts the ones you already did. The second pass is not optional on a tenor; it is where the tuning actually lands.
Why fifths feel different under the hand
On a guitar the strings are mostly a fourth apart, which puts four frets between adjacent strings and keeps chord shapes compact. Fifths put seven semitones between strings instead, so a scale covers far more of the neck per position and chords need a wider stretch — the same trade every viola and mandola player makes. What you get back is that the fingering for any scale is identical on every pair of strings, with no correction for a third anywhere, which is why fiddle tunes transfer to a tenor in Irish tuning without being rethought.
The 5th-fret trick guitarists use to tune by ear does not work here. On a tenor, the note a fifth up sits at the 7th fret: fret the C string at the 7th and you get G, matching the open 3rd. Same idea, different fret, and getting that wrong is the most common way a tenor ends up a whole tone out across the board.
Equal temperament and the open fifths
This tuner, like every chromatic tuner, works in equal temperament — and on an instrument tuned in fifths that is worth knowing about, because equal-tempered fifths are about 2 cents narrow of the pure 3:2 fifth your ear prefers. On a guitar that error hides inside the chord voicings. On a tenor it sits between two open strings, where a sustained double stop can show a slow beat even with both needles centred.
Two cents is small enough that most players never chase it, and centring the needle on all four strings is the right default — it keeps you in tune with fretted instruments and with anyone reading from a piano. Players who spend their time on open-string double stops sometimes tune the outer strings by ear to pure fifths instead and accept being a few cents off a piano. Both are defensible; what is not is doing half of each by accident. See what cents are for the arithmetic.
Frequently asked questions
What is the standard tuning for a tenor guitar?
C3–G3–D4–A4, low to high — written CGDA. The strings are a perfect fifth apart, the same layout as a tenor banjo, a mandola and a viola, so all four share one fingering vocabulary. At A=440 that is 130.81, 196.00, 293.66 and 440.00 Hz; the top string is concert A itself.
What is Irish tenor guitar tuning?
G2–D3–A3–E4 — GDAE, exactly one octave below a mandolin or a fiddle, and the same pitches as an octave mandolin. It is standard in Irish traditional music because the tunes are learned on fiddle and mandolin: a tenor in GDAE plays the melody straight from those fingerings, then drops to chords behind the next player. It wants heavier strings than CGDA — the low G is a fourth below the standard low C.
What is Chicago tuning?
D3–G3–B3–E4 — the top four strings of a standard guitar, so a guitarist can pick a tenor up and play immediately. It is a convenience tuning rather than a historical one. The cost is the fifths: the intervals become fourths and a third, so the mandola and tenor-banjo repertoire stops transferring, and so does the reason most people want a tenor in the first place.
How do I tell which tuning my tenor guitar is strung for?
Measure the lowest string, or read the packet if you still have it. CGDA sets run roughly .012–.036, Irish GDAE sets .014–.048, and a Chicago set is close to the top four of a light guitar set at about .012–.032. A low string of .014 or heavier means GDAE, and taking that up to CGDA over-tensions the neck and usually breaks the top string. Tune to what the gauges want first.
Is a tenor guitar the same as a baritone guitar?
No — closer to opposites, which is why the names get swapped. A tenor has four strings in fifths on a short 21–23 inch scale and sits above a guitar. A baritone has six strings in fourths on a long 26.5–30.5 inch scale and sits below one. The only thing they have in common is not being a standard guitar.