Tuning Analysis: C Diminished 7th Tuning

This intriguing tuning, aptly named 'C Diminished 7th Tuning', transforms your guitar into a resonant soundscape ideal for creating atmospheric and often dramatic sonic textures. The descriptor 'Droning' hints at its capability to provide a sustained, rich harmonic foundation, particularly with the repeated lower C notes. This tuning excels in genres requiring tension, mystery, or a touch of the avant-garde, such as blues, jazz, film scoring, or experimental music.

Technical Breakdown

The open strings of this tuning lay out the notes C2, C3, C3, D#4, F#4, A3. Analysing these notes reveals a clear harmonic structure:

• C (Root): Provided by the 6th, 5th, and 4th strings, offering a strong, resonant foundation.
• D# (Eb - Minor Third): On the 3rd string, providing the characteristic minor quality.
• F# (Gb - Diminished Fifth): On the 2nd string, introducing the diminished quality.
• A (Bbb - Diminished Seventh): On the 1st string, completing the diminished 7th chord.

Together, these notes form a full C diminished 7th chord (C-Eb-Gb-Bbb/A). This symmetrical chord is inherently unstable and ambiguous, lending itself to complex harmonic movements and voicings. Its unique structure means that moving it up or down in minor thirds will produce the same chord notes, albeit in different inversions, offering interesting melodic and harmonic possibilities.

Open Chords and Possibilities

The most obvious open chord is the C diminished 7th itself. However, because of the consistent C octaves on the lower strings and the diminished 7th chord built above, you can explore:

• Diminished Arpeggios and Scales: The open strings provide a direct pathway into diminished harmony, useful for creating tense or mysterious melodic lines.
• Droning Bass Lines: The repeated C notes on the lower strings are perfect for sustained bass tones, allowing the higher strings to weave melodic or dissonant lines above without clashing.
• Easier Chord Shapes: By fretting just one or two strings, you can quickly imply other diminished 7th chords (e.g., Ebdim7, Gbdim7, Adim7) or even create dominant 7b9 chords with relative ease due to the symmetrical nature of the diminished 7th. Experiment with simple barres across higher strings to discover new voicings.

How to Tune

To achieve a tuning from standard E-A-D-G-B-E, follow these specific string adjustments. Please note the recommendations regarding string gauge for significant changes:

• 6th String (Low E): Tune down 4 semitones from E2 to C2. Caution is advised as this is a significant drop in tension; consider a heavier gauge string for optimal playability.
• 5th String (A): Tune up 3 semitones from A2 to C3. This is a moderate increase in tension and generally safe for standard string gauges.
• 4th String (D): Tune down 2 semitones from D3 to C3. This is a common and safe adjustment for standard string gauges.
• 3rd String (G): Tune down 4 semitones from G3 to E3. Caution is advised as this is a significant drop in tension; consider a heavier gauge string for optimal playability.
• 2nd String (B): Tune down 5 semitones from B3 to F#3. A different string gauge is strongly advised due to this substantial drop in tension.
• 1st String (High E): Tune down 7 semitones from E4 to A3. A different string gauge is strongly advised due to this very significant drop in tension.

6th String: C2 (Low C)

5th String: C3 (Middle C)

4th String: C3 (Middle C)

3rd String: D#4 (Eb above Middle C)

2nd String: F#4 (Gb above Middle C)

1st String: A3 (A below Middle C)