Open C tuner
Tune your guitar to Open C: C G C G C E, from the thickest string to the thinnest. The tuner above is already set to Open C, so just tap Use microphone and play each string until it turns green.
Open C tuning notes
| String | Note | Frequency |
|---|---|---|
| 6th (thickest) | C2 | 65.41 Hz |
| 5th | G2 | 98.00 Hz |
| 4th | C3 | 130.81 Hz |
| 3rd | G3 | 196.00 Hz |
| 2nd | C4 | 261.63 Hz |
| 1st (thinnest) | E4 | 329.63 Hz |
Frequencies assume the standard reference pitch of A4 = 440 Hz.
How to get to Open C from standard
- Loosen the 6th string from E down 4 half steps to C.
- Loosen the 5th string from A down a whole step to G.
- Loosen the 4th string from D down a whole step to C.
- Tighten the 2nd string from B up a half step to C.
The other 2 strings stay where they are. Retune slowly and check each string twice, because changing the tension on one pulls slightly on the others.
What Open C is good for
A very low, wide C major chord across the open strings. Big and resonant, it suits fingerstyle and ambient playing. The low strings get slack, so pluck gently.
Other guitar tunings
| Tuning | Notes | What it is |
|---|---|---|
| Standard | E A D G B E | The default for almost everything. |
| Half step down | E♭ A♭ D♭ G♭ B♭ E♭ | Every string drops a semitone. |
| Whole step down | D G C F A D | Two semitones lower than standard. |
| C standard | C F B♭ E♭ G C | Every string two whole steps below standard. |
| B standard | B E A D F♯ B | Two and a half steps below standard, so the guitar sits close to a baritone. |
| Drop D | D A D G B E | Only the low E string changes. |
| Drop C♯ | D♭ A♭ D♭ G♭ B♭ E♭ | Drop D taken down another semitone, so every string is a half step below Drop D. |
| Drop C | C G C F A D | Drop D taken down a whole step. |
| Drop B | B F♯ B E G♯ C♯ | C♯ standard with the low string dropped to B. |
| Open G | D G D G B D | Strumming the open strings plays a G major chord, so a single finger across the neck gives you any major chord. |
| Open D | D A D F♯ A D | The open strings ring out a D major chord. |
| Open E | E B E G♯ B E | The open strings form an E major chord. |
| Open C | C G C G C E | A very low, wide C major chord across the open strings. |
| Open A | E A E A C♯ E | The open strings ring an A major chord. |
| DADGAD | D A D G A D | Neither major nor minor, so open strings drone underneath melodies. |
Gear that helps
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Open C tuning questions
What notes are in Open C tuning?
From the 6th string to the 1st, Open C is C G C G C E.
How do I tune my guitar to Open C?
Start in standard tuning, pick Open C in the tuner, then play each string and follow Tune up or Tune down until the note turns green. 4 strings change. The other 2 strings stay where they are.
How do I get back to standard tuning?
Choose Standard in the tuning menu, or open the guitar tuner, and tune each string back to E A D G B E.
Does it work on my phone?
Yes. It works in Safari on iPhone and Chrome on Android, as well as desktop browsers. Hold the phone close to the instrument and allow microphone access when asked.