Overview of the Open C Dmaj7 Tuning

This unique tuning transforms your guitar into an instrument capable of rich, complex harmonies right out of the open strings. Often referred to as Open C Dmaj7, it offers a distinct sonic landscape that blends a deep, resonant bass with bright, melodious upper registers.

Verbal Analysis: The Sound and Feel

The open strings of this tuning immediately present a D Major 7 chord (D-F#-A-C) with a prominent C in the bass. This creates a full, slightly melancholic, yet sophisticated sound reminiscent of jazz or contemporary folk music. The low C provides a sturdy foundation, allowing for a vast harmonic palette, while the higher D, F#, and A strings chime together beautifully, creating a bright and open D Major triad. The combination yields a feeling of expansive depth, making it suitable for introspective fingerpicking, atmospheric soundscapes, or even as a unique base for blues and rock. The wide intervals, particularly between the 6th (C) and 5th (A) strings, and the 5th (A) and 4th (D) strings, encourage fresh approaches to chord voicings and lead lines, pushing players beyond conventional shapes.

Technical Analysis: Intervallic Structure

From lowest to highest, the open strings are tuned to C2, A2, D3, F#4, A3, D4.

• String 6 (C2): Serves as the root of the tuning, providing a deep, resonant bass.
• String 5 (A2): A Major 6th above the C2, creating a strong harmonic relationship with the bass.
• String 4 (D3): A Perfect 4th above A2, completing the lower part of the D major triad.
• String 3 (F#4): A Major 3rd above D3, establishing the major quality of the chord.
• String 2 (A3): A Minor 3rd above F#4, or a Perfect 5th above D3, reinforcing the D major triad.
• String 1 (D4): A Perfect 4th above A3, providing an octave D to the 4th string, adding brightness and sustain.

The full open string chord is essentially a D Major 7 chord (D-F#-A-C) with the C as the lowest bass note, creating a distinctive C/Dmaj7 slash chord.

Accessible Chords and Playability

With the open C/Dmaj7 chord at your fingertips, moving this shape up the neck with a single-finger barre can quickly give you a variety of extended chords. For instance, barring at the 2nd fret would yield a D/Emaj7. The top four strings (D-F#-A-D) form a pure D Major triad, making it easy to adapt standard D Major-based voicings or create droning textures. The unique arrangement of the bass strings encourages experimentation with bass lines and rhythmic patterns not commonly found in standard tuning. Be prepared to discover new melodic and harmonic possibilities as you explore the fretboard with this inspiring tuning.

Tuning Notes Breakdown

• String 6 (Low E String): Tuned to C2
• String 5 (A String): Tuned to A2
• String 4 (D String): Tuned to D3
• String 3 (G String): Tuned to F#4
• String 2 (B String): Tuned to A3
• String 1 (High E String): Tuned to D4

How to Tune Your Guitar

To achieve the Open C Dmaj7 tuning, follow these specific string adjustments from standard EADGBe tuning:

• String 6 (Low E): Tune down 4 semitones to C2. Please exercise caution as tuning down 4 semitones is a significant adjustment; ensure your guitar's setup can handle the reduced tension.
• String 5 (A): Keep as is; no change (0 semitones) to A2.
• String 4 (D): Keep as is; no change (0 semitones) to D3.
• String 3 (G): Tune down 1 semitone to F#4.
• String 2 (B): Tune down 2 semitones to A3.
• String 1 (High E): Tune down 2 semitones to D4.

Important Note on String Gauge: When making significant tuning adjustments (generally exceeding 4 semitones up or down), it is often recommended to consider a different string gauge to maintain proper tension and avoid potential damage to your instrument or strings. For this tuning, the 6th string is tuned down 4 semitones, which is at the threshold where careful consideration of string tension is advised.