Cm11 Fourths Tuning Analysis

This custom 8-string guitar tuning, internally referred to as "Cm11," is designed to provide a rich, complex minor sound with improved clarity compared to lower tunings. The original designer noted, "Need something less muddy than low B til I can get a new effect pedal... Settling on this for right now." By raising the lowest string from a typical B1 to D1, this tuning successfully achieves a less muddy bottom end while retaining a powerful, full-range voice.

Verbal Analysis

The "Cm11 Fourths" tuning offers a distinctly dark and atmospheric sound, making it excellent for genres like progressive metal, jazz fusion, and ambient soundscapes. The predominant use of perfect fourth intervals across most strings facilitates easy power chords and open voicings, while the unique inverted interval between the 3rd (D#4) and 2nd (G3) strings provides an unexpected twist. This creates opportunities for interesting arpeggios and chord clusters that would be impossible in more conventional tunings. When played open, the strings resonate together to form a full Cm11 chord, offering a rich harmonic foundation without fretting a single note. This inherent complexity makes the tuning inspiring for improvisation and songwriting, providing immediate access to a sophisticated, minor-key tonality.

Technical Analysis

This is an 8-string guitar tuning. The open strings are pitched as follows, from thickest to thinnest:

• 8th String: D1
• 7th String: G1
• 6th String: C2
• 5th String: F2
• 4th String: A#3 (Bb3)
• 3rd String: D#4 (Eb4)
• 2nd String: G3
• 1st String: C4

The intervals between adjacent strings are mostly perfect fourths, providing a consistent fingering logic for many voicings:

• 8th String (D1) to 7th String (G1): Perfect Fourth
• 7th String (G1) to 6th String (C2): Perfect Fourth
• 6th String (C2) to 5th String (F2): Perfect Fourth
• 5th String (F2) to 4th String (A#3): Perfect Fourth (F to B♭)
• 4th String (A#3) to 3rd String (D#4): Perfect Fourth (B♭ to E♭)
• 3rd String (D#4) to 2nd String (G3): Descending Minor Sixth (E♭4 to G3)
• 2nd String (G3) to 1st String (C4): Perfect Fourth

The open strings collectively form a C minor eleventh (Cm11) chord (C, D, E♭, F, G, B♭), making it highly resonant and harmonically rich. The presence of the root (C), minor third (E♭), perfect fourth/eleventh (F), perfect fifth (G), minor seventh (B♭), and major ninth (D) creates a sophisticated open sound. The significant drop in pitch from the 3rd to the 2nd string (D#4 to G3) is a notable feature, creating an unexpected interval that can be exploited for unique voicings and arpeggiated figures.

Chords and Playability

With the consistent perfect fourths across most strings, standard power chords (root-fifth-octave) are easily formed by barring across three strings. The open Cm11 chord provides an instant harmonic backdrop. The inverted interval between the 3rd and 2nd strings will necessitate adaptation for conventional chord shapes but opens up possibilities for wider voicings and interesting diatonic or dissonant clusters. Scales and arpeggios that leverage this interval will yield unique melodic contours. Fingerpicking patterns can highlight the inherent Cm11 chord, while heavy riffing will benefit from the tuned-down, but clarified, lower register.

How to Tune

To achieve the Cm11 Fourths tuning, you will need to adjust your strings from a standard 8-string F# Standard tuning (F#1 B1 E2 A2 D3 G3 B3 E4). Each string must be tuned down by 4 semitones from its standard pitch. Please note that tuning down 4 semitones is at the threshold where a different string gauge might be advised for optimal string tension and playability. Using slightly lighter gauge strings for an 8-string set may provide a more balanced feel in this tuning.

• 8th String (Thickest): Tune down 4 semitones from F#1 to D1.
• 7th String: Tune down 4 semitones from B1 to G1.
• 6th String: Tune down 4 semitones from E2 to C2.
• 5th String: Tune down 4 semitones from A2 to F2.
• 4th String: Tune down 4 semitones from D3 to A#3 (B♭3).
• 3rd String: Tune down 4 semitones from G3 to D#4 (E♭4).
• 2nd String: Tune down 4 semitones from B3 to G3.
• 1st String (Thinnest): Tune down 4 semitones from E4 to C4.

Open String Notes for Cm11 Fourths Tuning

• 8th String: D1
• 7th String: G1
• 6th String: C2
• 5th String: F2
• 4th String: A#3
• 3rd String: D#4
• 2nd String: G3
• 1st String: C4