This is a powerful and resonant low tuning, famously used in modern progressive metal and djent genres, attributed to Mark Holcomb in a 2016 Guitar World issue. Based around the key of C minor, it offers a rich harmonic foundation with readily accessible complex chords.

Verbal Analysis

The tuning features a deep 'drop C' on the lowest string, providing a thick, guttural foundation for heavy riffs and breakdowns. The open strings resolve to a full C Minor (add9) chord (C-G-C-Eb-G-D), making it incredibly easy to achieve a harmonically rich sound with minimal effort. This tuning lends itself beautifully to open, ringing chords that evoke a dark, melancholic, yet powerful atmosphere. The lower strings are tuned to a wide C-G-C power chord, ideal for chunky rhythm playing, while the higher strings add the essential minor third (D#/Eb) and major ninth (D) for melodic complexity and voicings that cut through a dense mix.

Technical Analysis

This tuning is derived from standard E, with significant downtuning across all strings. The resulting notes are C2-G2-C3-D4#-G3-D4. Examining the intervals relative to the lowest C (C2):

• String 6 (C2): Root
• String 5 (G2): Perfect 5th
• String 4 (C3): Octave
• String 3 (D4#): Minor 3rd (Eb, enharmonically D#) - Two octaves above the root.
• String 2 (G3): Perfect 5th - Octave above the root.
• String 1 (D4): Major 9th - Two octaves above the root.

The open tuning creates a complete C Minor (add9) chord (C-G-Eb-D). This configuration simplifies playing full minor 9th chords across the fretboard by simply barring. The C-G-C power chord on the lower strings allows for easy movement of root-fifth voicings, while the carefully chosen upper notes provide harmonic depth and interest. This tuning facilitates both heavy, chugging rhythms and complex, melodic lead lines that highlight the minor 9th tonality.

How to Tune

To achieve this tuning from standard E, follow these instructions. Please note that significant downtuning (4 semitones or more) may require a heavier gauge string set to maintain proper tension and intonation, and care should be taken to avoid string breakage when making large pitch changes.

• String 6 (Low E): Tune down 4 semitones to C2. (Caution: Tuning down 4 semitones is a significant change; a heavier gauge string is advised for optimal performance.)
• String 5 (A): Tune down 2 semitones to G2.
• String 4 (D): Tune down 2 semitones to C3.
• String 3 (G): Tune down 4 semitones to D4#. (Caution: Tuning down 4 semitones is a significant change; a heavier gauge string is advised for optimal performance. Note: Ensure you are tuning to the specified D4#, as the instruction implies reaching this specific note via the provided semitone movement.)
• String 2 (B): Tune down 4 semitones to G3. (Caution: Tuning down 4 semitones is a significant change; a heavier gauge string is advised for optimal performance.)
• String 1 (High E): Tune down 2 semitones to D4.

Always use a reliable tuner and check your intonation after changing tunings, especially with such large pitch shifts.

String 6: C2 (Low C)

String 5: G2 (G an octave below middle C)

String 4: C3 (Middle C)

String 3: D4# (D sharp an octave above middle C)

String 2: G3 (G an octave above middle C)

String 1: D4 (D an octave above middle C)