1.
Release the pitch of the low E-string (sixth string) by one and a half steps, so that the sound source of the string is a full octave below the middle C. You can use an outside tuning source for this, or you can set the open sixth string to an octave below the note that sounded in the third fret of the A-string.
2.
Release the pitch A string with a full step to an audio source of G. If you are not using an external tuning source, tune the fifth string to an octave below the tone of the open G string.
3.
Release the pitch of the D-string (fourth string) with a full step to a sound source of C. If you use a piano as your tuning source, this new pitch is found in the middle C.
4.
Leave the G-string (third string) alone. Of course, you need to check the tuning, but open C setting does not change the sound source of this tone.
5.
Raise the pitch of the B-string (second string) by half a step to a swinging tone C. If you do not have an external tuning source, touch the g-string at the fifth fret and tune the B-string to that note.
6.
Leave the high E-string (first string) alone. You may need to fine-tune the first string, but open C-tuning does not require any major settings for this. Check if all other strings are tuned, and you’re good to go with a guitar tuned to open C.
Tips and warnings
Open tunings is one of the guitarist’s best friends. By tuning the guitar to an open chord, you can take advantage of the automatic harmony created when you tune the open strings. Learn how to tune a guitar to open C-tuning for Examples, opens up a world of possibilities. Take a guitar and a tuner and give the six-star brand new sound.
Source:danspela.com