The Open C6 tuning for Guitar, known also as Open C Tuning, offers a profound and resonant sound, ideal for a variety of styles from intricate fingerpicking to robust blues and melodic compositions. This specific configuration, resulting in the notes C-A-C-G-C-E from low to high, is notably used in the instrumental masterpiece "Bron-y-Aur."

Technical Analysis:

In this tuning, strumming all open strings produces a rich C6 chord (C-E-G-A). The strategic placement of C notes across the 6th, 4th, and 2nd strings establishes a powerful root foundation, spanning multiple octaves. The 3rd string's G provides the perfect fifth, the 1st string's E contributes the major third, and the 5th string's A completes the distinct major sixth harmony. This arrangement not only allows for effortless strumming of C6, C major, and C minor (by flattening the E string at the first fret) chords but also facilitates intuitive arpeggio playing and the creation of lush, ringing drones. The closely voiced C notes make it particularly adaptable for open string melodic phrases and complex chord voicings that resonate with impressive sustain.

How to Tune:

Adjusting to Open C6 requires precise string movements. Please proceed carefully, especially with the more significant changes, and use a reliable tuner:

• String 6 (Low E): Tune down 4 semitones to C2. This is a substantial drop. While within the practical range for many standard gauge strings, tuning down by 4 semitones is at the threshold where a heavier gauge string might offer improved stability and tone for this specific tuning, especially if played frequently.
• String 5 (A): Keep as is; no change (0 semitones) remaining at A2.
• String 4 (D): Tune down 2 semitones to C3.
• String 3 (G): Keep as is; no change (0 semitones) remaining at G3.
• String 2 (B): Tune up 1 semitone to C4. Exercise caution during this adjustment, as tuning up increases string tension, as noted in the original description. However, a 1-semitone increase is generally safe for standard strings.
• String 1 (High E): Keep as is; no change (0 semitones) remaining at E4.

String 6: C2 (The standard Low E string is tuned down 4 semitones to C)

String 5: A2 (The standard A string remains unchanged)

String 4: C3 (The standard D string is tuned down 2 semitones to C)

String 3: G3 (The standard G string remains unchanged)

String 2: C4 (The standard B string is tuned up 1 semitone to C)

String 1: E4 (The standard High E string remains unchanged)