The "Open IDC" tuning is a truly unique and exploratory setup for the guitar, living up to its description as "strange but interesting." Unlike many open tunings that immediately resolve to a major or minor chord, this tuning leans into dissonance and suspended qualities, offering a distinct and atmospheric sonic palette.

Technical Analysis

The open strings are tuned to:

• 6th String (Low E string position): D♯3 (Root)
• 5th String (A string position): G♯3 (Perfect 4th above D♯3)
• 4th String (D string position): F3 (Major 2nd above D♯3)
• 3rd String (G string position): G♯4 (Octave + Perfect 4th above D♯3)
• 2nd String (B string position): A♯4 (Octave + Perfect 5th above D♯3)
• 1st String (High E string position): D♯5 (Two Octaves above D♯3)

This configuration results in a complex open voicing. The notes D♯, F, G♯, and A♯ are present across the open strings (with octave repetitions). This collection of intervals creates a D♯sus2sus4 chord (D♯, F, G♯, A♯). The Major 2nd (F) and the Perfect 4th (G♯) intervals relative to the root D♯ contribute to its distinctive suspended and often atmospheric sound. The presence of the A♯ (Perfect 5th to D♯) further solidifies this harmonically rich, yet unresolved, character.

Verbal Observations & Chordal Possibilities

Strumming all open strings yields an immediate, evocative D♯sus2sus4 chord. This isn't a traditionally "pretty" major or minor sound, but rather something more ethereal, suited for ambient textures, drone music, or a dark, moody accompaniment. The close proximity of the F3 (Major 2nd) to the D♯3 (Root) on the lower strings creates a natural harmonic tension that can be exploited for expressive playing.

Due to the consistent interval structure of D♯ - F - G♯ - A♯ across the open strings, barring all strings at any single fret will transpose this D♯sus2sus4 shape up the neck. For example, barring at the first fret would produce an Esus2sus4 chord (E, F♯, A, B). This makes it straightforward to create a compelling series of suspended chords with a consistent voicing, ideal for rhythmic strumming or arpeggiated patterns where a sense of unresolved yearning is desired. Experimentation with partial barres or fingerings that emphasize specific intervals will unlock a wide range of unique chord voicings and melodic opportunities.

How to Tune

To achieve the "Open IDC" tuning from standard E-A-D-G-B-E, follow these string adjustments:

• 6th String (Low E): Tune down 1 semitones to D♯3.
• 5th String (A): Tune down 1 semitones to G♯3.
• 4th String (D): Tune up 3 semitones to F3.
• 3rd String (G): Tune up 1 semitones to G♯4.
• 2nd String (B): Tune down 1 semitones to A♯4.
• 1st String (High E): Tune down 1 semitones to D♯5.

Important Note: All string movements in this tuning are within a moderate range. However, always tune your guitar carefully and gradually, being mindful of your instrument's tension and string gauge.