Tuning Overview: Open C Minor

This is a rich and resonant open C minor tuning for the guitar, specifically voiced as C-G-Eb-G-C-C (from low to high string, based on the tuning movements). It offers a powerful minor tonality, making it ideal for blues, slide guitar, dark folk, and various rock genres where a minor drone or arpeggio is desired. The tuning creates an immediate C minor chord when strummed open, allowing for expressive melodic and rhythmic playing without complex fingerings.

Technical Analysis

• Instrument Type: Guitar
• Base Chord: The open strings form a clear C minor chord (C, Eb, G). The tuning effectively duplicates the root (C) on three strings (Low C2, C4, C4) and the perfect fifth (G) on two strings (G2, G3), creating a very full and harmonic sound. The minor third (Eb3, also known as D#3) is centrally placed on the 4th string.
• Voicing: The notes are C2-G2-Eb3-G3-C4-C4. This provides a deep, resonant bass with the C2 and G2, a strong minor character with Eb3, and a bright, chiming quality from the doubled C4s on the high strings, which will sustain beautifully.
• Fretboard Application: This tuning is highly adaptable for slide guitar, as a single barre across all strings at any fret will reliably produce a minor chord. For example, barring at the 3rd fret yields an Eb minor chord, and at the 5th fret, an F minor chord. This makes key changes straightforward and intuitive for chordal playing.
• Chord Accessibility: While the tuning itself is C minor, it lends itself well to exploring related chords and scales. The original description states that this tuning was conceived to find an easier way to play a D minor chord from a standard Open C tuning (CGEGCC). Although this is not an open D minor tuning, the C minor foundation provides a strong base from which to build D minor (D-F-A) and other minor or dominant chords within the key. For instance, playing the 2nd fret on the 3rd G string (A), and the 5th fret on the 6th C string (F), while leaving the 5th G string open, can begin to outline D minor voicings. The overall structure provides a powerful springboard for minor key improvisations and melodic exploration.
• Harmonic Potential: The open C-G-Eb-G-C-C arrangement offers a rich palette for both chordal accompaniment and melodic leads, with ample opportunities for droning strings and resonant harmonics due to the multiple octave and unison notes.

How to Tune

To achieve the Open C Minor tuning, start from standard EADGBe tuning (E2-A2-D3-G3-B3-E4) and adjust each string as follows:

• String 6 (Low E): Tune down 4 semitones from E2 to C2. (Note: Tuning down 4 semitones is a significant adjustment; consider a heavier gauge string for optimal tension and tone, or proceed with caution.)
• String 5 (A): Tune down 2 semitones from A2 to G2.
• String 4 (D): Tune up 1 semitone from D3 to D#3 (Eb3).
• String 3 (G): Keep as is; no change (0 semitones). The string remains G3.
• String 2 (B): Tune up 1 semitone from B3 to C4.
• String 1 (High E): Tune down 4 semitones from E4 to C4. (Note: Tuning down 4 semitones is a significant adjustment; consider a heavier gauge string for optimal tension and tone, or proceed with caution.)

When tuning strings significantly up or down (generally exceeding 4 semitones in either direction), it's often advisable to use a different gauge string to maintain proper string tension, prevent premature string wear, or avoid potential damage to the instrument. In this tuning, String 6 and String 1 are tuned down 4 semitones, which is at the threshold where a change in string gauge might be beneficial for long-term playability and optimal tone, although it's usually manageable with standard light or medium gauge strings if done carefully.

Tuning Notes (Low to High)

• String 6: C2
• String 5: G2
• String 4: D#3 (Eb3)
• String 3: G3
• String 2: C4
• String 1: C4