Open C tuner
Tune to Open C (C G C G C E) with your microphone or by ear.
Open C
Start tuner
Your browser asks for the microphone when you press Start. Nothing is recorded or uploaded.
Tap a string to hear it and tune that string.
Open C spreads a C major chord across the strings from a deep low C: C G C G C E. Four strings move from standard: the 6th drops four semitones to C, the 5th and 4th drop a whole step, and the 2nd rises a semitone to C.
It is popular for fingerstyle and ambient playing, where the open strings ring for a long time under a melody.
Open C: notes and frequencies
| String | Note | Pitch | Frequency |
|---|---|---|---|
| 6 | C | C2 | 65.41 Hz |
| 5 | G | G2 | 98.00 Hz |
| 4 | C | C3 | 130.81 Hz |
| 3 | G | G3 | 196.00 Hz |
| 2 | C | C4 | 261.63 Hz |
| 1 | E | E4 | 329.63 Hz |
From standard tuning to Open C
- String 6: lower it from E2 to C2, 4 semitones down.
- String 5: lower it from A2 to G2, 2 semitones down.
- String 4: lower it from D3 to C3, 2 semitones down.
- String 3: stays at G3.
- String 2: raise it from B3 to C4, 1 semitone up.
- String 1: stays at E4.
The 2nd string goes up, from B to C, while the others come down. Tune it last and gently.
Tune to Open C by ear
Tune string 6 (C2) to a reference first: tap it in the tuner above, or use a piano or another instrument. Then tune each string to one that is already in tune:
- Play string 6 at fret 7, then tune open string 5 until the two sound the same (G2).
- Play string 5 at fret 5, then tune open string 4 until the two sound the same (C3).
- Play string 4 at fret 7, then tune open string 3 until the two sound the same (G3).
- Play string 3 at fret 5, then tune open string 2 until the two sound the same (C4).
- Play string 2 at fret 4, then tune open string 1 until the two sound the same (E4).
Learning a song in Open C?
Record it or upload it, and Tabtify turns it into tab you can play along with. Choose Open C under Tuning in the converter's options so the frets match your guitar.
Turn a recording into tabOpen C tuner FAQ
What are the notes of Open C?
From string 6 to string 1: C2, G2, C3, G3, C4, E4. With A4 at 440 Hz, that is 65.41 Hz, 98.00 Hz, 130.81 Hz, 196.00 Hz, 261.63 Hz, 329.63 Hz.
Does Open C need heavier strings?
The low C sits four semitones under standard and can feel loose on a light set. A medium set, such as 12 to 53 on an acoustic, holds it better.
How do I play chords in Open C?
Barre all six strings: open is C, the 5th fret F, the 7th fret G.