Sandberg's Open C Ambience is a truly unique and expressive guitar tuning, designed to inspire creative playing with its rich open voicings and distinctive harmonic palette. As its creator describes, it aims for an "interesting diminished sound" and "beautiful colors" in chords, moving away from conventional major or minor sonorities. The tuning's wide intervals and open string resonance make it particularly suited for ambient soundscapes, fingerstyle pieces, and experimental music where a sense of space and intriguing harmonic tension is desired. It encourages players to explore new melodic and harmonic ideas, as familiar chord shapes will yield entirely new sounds, opening up fresh creative pathways.

Technical Analysis

This tuning establishes an open C tonality, with the 6th and 1st strings both tuned to C (C2 and C4 respectively), creating a strong fundamental and an octave drone. The full open string notes are C2-A2-D3-G3-A3-C4. While centered around C, the absence of a major or minor third (E or E♭) in the open strings contributes to the ambiguous and "suspended" character mentioned by the creator. Instead, we find the Major 6th (A) and Major 2nd/9th (D) prominently featured, forming an open Cmaj6(add9) chord without the 3rd.

Key intervals:

• String 6 (C2) to String 5 (A2): A Major 6th (9 semitones).
• String 5 (A2) to String 4 (D3): A Perfect 4th (5 semitones).
• String 4 (D3) to String 3 (G3): A Perfect 4th (5 semitones).
• String 3 (G3) to String 2 (A3): A Major 2nd (2 semitones).
• String 2 (A3) to String 1 (C4): A Minor 3rd (3 semitones).

The stacked perfect 4ths between strings 5, 4, and 3 (A-D-G) provide a rich, resonant base, excellent for power chords and modal explorations. The higher strings (G-A-C) present a Gsus4-like cluster (G, A, C), which can be easily expanded into various chords. The overall open voicing of C-A-D-G-A-C offers a C6(add9) tonality with a distinctive, airy quality, fostering the "beautiful colors" described. The "diminished sound" may arise from the potential for creating unresolved or dissonant intervals against the open strings, or from specific inversions that quickly lead to diminished or half-diminished voicings with minimal fretting.

Accessible Chords & Voicings:

• Open C Chords: The strong C root and octave, along with the G (5th) on string 3, make C major, C6, Cmaj9(no3rd), and suspended C chords readily available and resonant.
• A-minor/D-sus Chords: The prominent A notes on strings 5 and 2, combined with D on string 4, allow for easy voicings of A minor family chords (e.g., Am7sus4 by fretting a C on string 4, 2nd fret) or Dsus2/Dsus4 voicings.
• Modal Explorations: The absence of a definitive 3rd in the open strings makes this tuning highly versatile for modal playing. By fretting a major or minor third (E or E♭) on the D string (string 4), you can quickly establish a C major or C minor tonality, respectively, and then build on it.
• Drone & Rhythmic Playing: The repeated C and A notes across octaves provide excellent drone capabilities, perfect for rhythmic patterns or atmospheric soundscapes.

How to Tune to Sandberg's Open C Ambience

To achieve this unique tuning, you will need to adjust several strings from standard EADGBe tuning. Please proceed with care, especially when significantly altering string tension. For movements exceeding -4 or +4 semitones, it is generally recommended to consider using a different string gauge to ensure optimal playability and string longevity.

• String 6 (Low E): From standard E2, tune down 4 semitones to C2. (Note: Tuning down 4 semitones is a significant drop; consider a heavier gauge string for optimal performance.)
• String 5 (A): From standard A2, keep as is; no change (0 semitones). Remains A2.
• String 4 (D): From standard D3, keep as is; no change (0 semitones). Remains D3.
• String 3 (G): From standard G3, keep as is; no change (0 semitones). Remains G3.
• String 2 (B): From standard B3, tune down 2 semitones to A3.
• String 1 (High E): From standard E4, tune down 4 semitones to C4. (Note: Tuning down 4 semitones is a significant drop; consider a heavier gauge string for optimal performance.)