The Open C Low tuning is a powerful and resonant open tuning for guitar, frequently employed for its deep, rich sound and ease of playing major chords. As its name suggests, when all strings are strummed open, they collectively form a C Major chord, specifically a C Major triad spread across the instrument: C2-G2-C3-E3-G3-C4. This provides a full, harmonically complete sound without fretting any notes, making it incredibly versatile for drone-based music, heavy riffs, or expansive acoustic pieces.

This tuning is known for its use by artists like Oxbow in their 2007 song "Its the Giving, Not the Taking" and Needtobreathe on "Lay Em Down," showcasing its adaptability across different genres, from experimental rock to modern rock/pop. The significant down-tuning of several strings (specifically the 6th, 2nd, and 1st strings by a major third) contributes to its characteristic deep timbre and allows for a slacker string feel, though heavier gauge strings might be advisable to maintain optimal tension and intonation, especially for those who play with a strong attack or prefer less string floppiness.

Technically, Open C Low is characterized by a fundamental C note on the lowest string, with the entire tuning structured around the C Major triad (C, E, G). The intervals from the lowest C are: perfect fifth (G), octave (C), major third (E), perfect fifth (G), and another octave (C). This arrangement simplifies chord voicings significantly; a single finger barring across any fret will instantly produce a major chord in that key. For instance, barring at the 1st fret yields a C# Major, and at the 2nd fret, a D Major. Beyond simple barring, the inherent C-E-G structure makes it straightforward to derive other related chords, such as G Major (often accessible with open strings and one or two fretted notes), F Major, or various minor and suspended chords by adjusting only a few fingers from the open position.

How to Tune to Open C Low

To achieve the Open C Low tuning from standard E Standard tuning, follow these steps:

• 6th String (Low E): Tune down 4 semitones to C2.
• 5th String (A): Tune down 2 semitones to G2.
• 4th String (D): Tune down 2 semitones to C3.
• 3rd String (G): Tune down 3 semitones to E3.
• 2nd String (B): Tune down 4 semitones to G3.
• 1st String (High E): Tune down 4 semitones to C4.

As all strings are tuned down, particularly the 6th, 2nd, and 1st strings by 4 semitones from standard, you may find that the string tension is considerably looser than standard tuning. For optimal playability, intonation, and to prevent excessive string floppiness or buzzing, using a heavier gauge string set is generally recommended for this tuning.

Tuning Notes Breakdown

• 6th String (Low E): Tuned down to C2.
• 5th String (A): Tuned down to G2.
• 4th String (D): Tuned down to C3.
• 3rd String (G): Tuned down to E3.
• 2nd String (B): Tuned down to G3.
• 1st String (High E): Tuned down to C4.