Tuning Overview: Open C minor 7th (C Bb Eb G Bb Eb)

This intriguing tuning, known as "Open Eb/C," is specifically designed for a distinctive sound often associated with math-rock and experimental genres. It builds upon a powerful foundation by dropping the 6th string to a C, which immediately creates a deep, resonant bass. The overall open string configuration from low to high is C2-A#3-D#4-G3-A#4-D#5. Technically, this translates to C-Bb-Eb-G-Bb-Eb, forming a rich Open C minor 7th chord when all strings are strummed openly.

The deliberate choice to tune the open strings to form a C minor 7th chord provides a lush and harmonically complete canvas. The presence of the root (C), minor third (Eb/D#), perfect fifth (G), and minor seventh (Bb/A#) across the open strings makes this tuning incredibly versatile for expressive playing and intricate harmonic exploration.

Sonic Characteristics & Playability:

• Open Chords: Strumming all open strings yields a full and resonant C minor 7th chord. This foundational chord can be easily moved up and down the neck using barre techniques, offering a wide array of minor 7th voicings across the fretboard.
• Harmonic Opportunities: A key feature of this tuning is the repetition of Bb (A#) and Eb (D#) notes on different string pairs (5th & 2nd, 4th & 1st respectively). This arrangement is excellent for creating drones, tapped harmonies, and intricate arpeggios, allowing for sustained tones and complex melodic lines that ring out beautifully, as noted in the original description.
• Math-Rock / Experimental Appeal: The unique intervals and the dramatically dropped 6th string to C contribute to a darker, more expansive sound palette. This tuning encourages experimentation with dissonances, suspensions, and non-standard melodic phrasing, making it ideal for the intricate, often percussive, and harmonically rich stylings prevalent in math-rock and other progressive genres.
• Chord Shapes Within Reach: Beyond the primary open C minor 7th chord, the consistent intervals make other chord shapes intuitively accessible. Barre chords at various frets will naturally yield other minor 7th chords. Furthermore, experimenting with partial barres or two-finger shapes can easily create C minor, Eb major, G minor, or Bb major feels rooted on different strings. For instance, fretting just the 6th string at the 3rd fret (Eb) while leaving the others open gives an Eb major 7th flavour (Eb G Bb Eb), or fretting at the 5th fret (F) can yield an F minor 7th.

String 6 (Low E): Tuned down significantly to C2. This provides a deep, resonant bass note and acts as the root of the open C minor 7th chord.

String 5 (A): Tuned up to A#3 (Bb3). This note forms the minor seventh of the open C minor 7th chord, adding its characteristic color.

String 4 (D): Tuned up to D#4 (Eb4). This is the minor third of the open C minor 7th, crucial for its minor tonality.

String 3 (G): Retained at G3. This note provides the perfect fifth of the open C minor 7th chord, giving it stability and fullness.

String 2 (B): Tuned down to A#4 (Bb4). This note is an octave higher than the 5th string's A#3, reinforcing the minor seventh.

String 1 (High E): Tuned down to D#5 (Eb5). This note is an octave higher than the 4th string's D#4, reinforcing the minor third and completing the open chord.

Open Tuning Summary:

• String 6: C2
• String 5: A#3 (Bb3)
• String 4: D#4 (Eb4)
• String 3: G3
• String 2: A#4 (Bb4)
• String 1: D#5 (Eb5)

How to Tune:

To achieve this "Open Eb/C" tuning from standard E Standard tuning (E-A-D-G-B-E), follow these precise string adjustments:

• String 6 (Low E): Tune down 4 semitones to C2. Note: A significant drop. If tuning repeatedly, consider a heavier gauge string for optimal tension and tone.
• String 5 (A): Tune up 1 semitones to A#3.
• String 4 (D): Tune up 1 semitones to D#4.
• String 3 (G): Keep as is; no change (0 semitones).
• String 2 (B): Tune down 1 semitones to A#4.
• String 1 (High E): Tune down 1 semitones to D#5.

General Advisory: For string movements exceeding 4 semitones up or down (e.g., String 6 in this tuning), it is often recommended to use a different gauge string to maintain proper tension, intonation, and string longevity, and to prevent potential damage to your guitar.