This is an exhilarating Open C Major tuning for a 7-string Guitar, aptly named "Open C major on 7". As its name suggests, this tuning transforms your instrument into a giant C major chord when all strings are played open. It's designed to provide a rich, resonant harmonic foundation, making it perfect for slide guitar, drone-based music, or simply for exploring new sonic textures.

Technical Analysis

The tuning follows a clear C Major triad structure across all seven strings: C2-E2-G2-C3-E3-G3-C4. This arrangement ensures that every open string is a component of the C major chord, creating a powerful, full-bodied sound. The intervals from the lowest C2 string are:

• String 7 (C2): Root
• String 6 (E2): Major Third
• String 5 (G2): Perfect Fifth
• String 4 (C3): Octave
• String 3 (E3): Major Tenth
• String 2 (G3): Perfect Twelfth
• String 1 (C4): Double Octave

Chords and Playability

The most immediate benefit of this tuning is the instant access to a full C Major chord by simply strumming all open strings. This makes it incredibly intuitive for playing in the key of C. Beyond that, the open major tuning facilitates easy transposition:

• Barre Chords: By fretting all seven strings at any given fret, you instantly create a major chord. For example, barring at the 1st fret gives you C# Major, at the 2nd fret D Major, and so on. This simplifies playing major chords across the fretboard.
• Power Chords: The repetitive C-G-C and E-G-C patterns mean power chords (root-fifth-octave) are readily available with minimal finger movement.
• Drone Effects: The sustained C major harmony is ideal for creating drone effects, especially on the lower strings, providing a rich backdrop for melodies.
• Accessible Related Chords: While primarily C Major, common related chords such as G Major (V) and F Major (IV) can often be found with relatively simple shapes, building upon the established harmonic foundation. Minor chords would typically require specific fretting to alter the major third.

How to Tune

To achieve this "Open C Major 7-String" tuning, you will adjust your standard 7-string guitar strings (assuming a standard B-E-A-D-G-B-E tuning) as follows. Please exercise caution when tuning, especially with larger pitch changes, and consider string gauge suitability.

• 7th String (Lowest B): Tune up 1 semitone to C2.
• 6th String (E): Keep as is; no change (0 semitones) to E2.
• 5th String (A): Tune down 2 semitones to G2.
• 4th String (D): Tune down 2 semitones to C3.
• 3rd String (G): Tune down 3 semitones to E3.
• 2nd String (B): Tune down 4 semitones to G3.
• 1st String (Highest E): Tune down 4 semitones to C4.

Important Note on String Gauges: The maximum drop is 4 semitones (on the 2nd and 1st strings), which is at the threshold where a different string gauge might be advisable for optimal string tension, feel, and longevity. Exceeding -4 or +4 semitones generally calls for a dedicated string set to prevent floppiness or undue stress on the neck.

The open strings for this tuning are as follows:

String 7: C2 (Lowest String)

String 6: E2

String 5: G2

String 4: C3

String 3: E3

String 2: G3

String 1: C4 (Highest String)