Open C Tuner

How to Use This Open C Tuner

1. Press Start Recording on the tuner above and allow microphone access.
2. The Open C preset is already selected.
3. Drop string 6 from E all the way down to C (65.41 Hz) — two whole steps, the largest move of any tuning on this site.
4. Drop string 5 from A to G (98.00 Hz) and string 4 from D to C (130.81 Hz).
5. Leave string 3 alone — G is already correct.
6. Raise string 2 from B to C (261.63 Hz) — a semitone up, the only string that tightens.
7. Leave string 1 alone — E is already correct.
8. Strum, then run two or three more passes. Five strings moving, three of them a long way, means substantial tension change and a lot of settling.

What is Open C Tuning?

Open C tunes the strings to C G C G C E, sounding a C major chord across the full range of the instrument. It is the deepest of the common open tunings: the low C at 65.41 Hz sits a full fourth below standard tuning's low E, close to the range of a baritone guitar.

The voicing stacks three C's — C2, C3, and C4 — with two G's between them and a single E on top. That triple root over a doubled fifth is what gives Open C its enormous, piano-like resonance, and why it is so popular for solo acoustic arrangements that have to fill space on their own.

Why Guitarists Use Open C

• Sheer depth. Nothing else in standard six-string territory sounds this big. For solo fingerstyle, the extra low end replaces a bass player.
• Sustained drones. Three C's and two G's ringing open means you can hold a pedal tone under almost anything.
• Simple shapes, huge sound. As with all open tunings, one or two fingers produce full chords, leaving your other fingers free for melody.
• Percussive playing. The slack low strings respond well to slapping and body percussion, which is why modern percussive fingerstyle players gravitate to it.

Famous Songs in Open C

• Friends — Led Zeppelin: Jimmy Page's Open C arrangement, one of the earliest prominent uses in rock.
• Ocean — John Butler: A landmark of modern percussive fingerstyle, built on Open C's resonance.
• Burden of Tomorrow — The Tallest Man on Earth: Open C used for folk songwriting rather than instrumental display.
• Pretty Noose — Soundgarden: Chris Cornell applying Open C to heavy rock.

Starter Shapes

• C major: all strings open.
• F major: barre the 5th fret.
• G major: barre the 7th fret.
• A minor: barre the 9th fret.
• Csus2: all open, but lift the 1st string — the E is the only third in the tuning, so muting it removes the tonality.

The String Gauge Problem

Open C asks more of your strings than any other tuning here. Dropping the 6th string from E2 to C2 removes roughly 40% of its tension. A standard .046 at that pitch is genuinely floppy — it will buzz against the frets, intonate unpredictably, and sound indistinct rather than deep.

The fix is a heavier low end. Many Open C players use a custom set with a .056 to .060 on the 6th string while keeping normal gauges on top, which is why "heavy bottom" sets exist. After fitting them, expect to check neck relief and reset the intonation.

Troubleshooting

The tuner cannot detect my low C.At 65.41 Hz this is at the edge of what a laptop or phone microphone reproduces. Pluck firmly over the soundhole or neck pickup, mute the other strings, and let it ring for a full second.

The low C sounds dull and buzzy rather than deep. Gauge problem, not tuning. See above.

It will not settle. Three strings moving a long way shifts the neck substantially. Three full passes with hard strumming in between is normal for Open C, not excessive.

If Open C is too much for your current strings, try Open D or Open G first — both give you the open-tuning experience with far less setup. Or read the full guide to alternate guitar tunings.