Verbal and Technical Analysis

The 'Open C unison 7-str' tuning transforms your 7-string guitar into a powerhouse of rich, resonant C major tonality. As the name suggests, the open strings naturally form a C Major chord, providing a deeply satisfying, full-bodied sound when strummed openly. The standout feature here is the unison C4 on strings 3 and 2. This doubling creates an incredibly thick, shimmering texture, making arpeggiated figures and sustained notes ring out with exceptional clarity and presence.

This tuning is a fantastic foundation for genres requiring a heavy, percussive low end combined with melodic upper registers. The low C (C2) on string 7 offers an immense depth, ideal for chugging riffs and extended range bass lines. The open Gs (G2, G3) provide perfect fifths, underpinning the C major harmony, while the high E (E4) completes the major triad on top.

The tuning's structure, particularly the open C Major, makes several common chords very accessible. C Major is your home base. Barre chords become incredibly powerful: a barre across the 5th fret yields an F Major, and a barre across the 7th fret gives you a G Major, both with the added richness of the low C. The description highlights that "The unison string sweetens the minor chords." This is particularly true; adding an Eb (minor third) on the appropriate fret will create a C minor chord where the doubled C4s will give it a unique, haunting quality, perfect for expressive melodic lines or dark, introspective passages.

Tuning Notes

Here are the notes for each string in this powerful 7-string Open C Unison tuning:

• String 7: C2 (Lowest C, deep and resonant)
• String 6: G2 (A perfect fifth above the lowest C)
• String 5: C3 (An octave above the lowest C)
• String 4: G3 (An octave above G2)
• String 3: C4 (The first of the unison C's, providing harmonic richness)
• String 2: C4 (The second unison C, doubling the pitch for a thick, sustained sound)
• String 1: E4 (The major third, completing the open C Major chord)

How to Tune

Please approach tuning with care, especially with significant semitone changes. For reference, these instructions assume a standard 7-string tuning (B E A D G B E).

• String 7 (B): To reach C2, tune String 7 up 1 semitone.
• String 6 (E): To reach G2, tune String 6 up 3 semitones.
• String 5 (A): To reach C3, tune String 5 up 3 semitones.
• String 4 (D): To reach G3, tune String 4 up 5 semitones. Caution: Tuning this string up 5 semitones is a significant change. A heavier gauge string may be advisable to prevent breakage and ensure optimal tone and tension.
• String 3 (G): To reach C4, tune String 3 up 5 semitones. Caution: Tuning this string up 5 semitones is a significant change. A heavier gauge string may be advisable to prevent breakage and ensure optimal tone and tension.
• String 2 (B): To reach C4, tune String 2 up 1 semitone.
• String 1 (E): Keep as is; no change (0 semitones). The target note is E4.