Welcome to the "C and G octave tuning," a formidable setup for an 8-string guitar designed to deliver immense low-end power and unique harmonic possibilities. As described, it's akin to a standard Drop C tuning, but significantly extended with additional C and G octaves to plumb the sonic depths, making it perfect for genres demanding heavy, resonant, and expansive soundscapes.

Verbal Analysis

This tuning immediately announces itself with a thunderous presence, providing a deep, resonant foundation in C. The strategic placement of G notes alongside C octaves across the lowest strings creates a rich, full-bodied sound that's both powerful and harmonically interesting. It's built for impact, allowing for massive power chords and riffs that vibrate through the floor. The higher strings, while not strictly following the C-G pattern, offer a distinct melodic and harmonic palette, breaking away from the pure power chord structure to introduce open, suspended voicings. Imagine a sound that is both crushing in its low end and surprisingly open in its higher registers, catering to both brutal rhythm work and atmospheric textures.

Technical Analysis

This is an 8-string guitar tuning with the following open notes from lowest to highest: C1 G1 C2 G2 C3 F3 A3 D4. The most striking feature is the foundation laid by the first five strings (C1-G1-C2-G2-C3). This configuration establishes a strong C power chord across multiple octaves, making it incredibly easy to achieve massive, resonant power chords by simply barring these strings. The intervals are meticulously chosen to maximize a C-centric tonality:

• String 8 (C1): The fundamental root.
• String 7 (G1): A perfect fifth above C, solidifying the power chord.
• String 6 (C2): An octave above String 8.
• String 5 (G2): An octave above String 7.
• String 4 (C3): An octave above String 6, completing three full octaves of C.

The subsequent strings diverge from this pattern, introducing interesting extensions:

• String 3 (F3): A perfect fourth above C3, introducing a suspended or Lydian flavor.
• String 2 (A3): A major third above F3, creating a partial F major triad.
• String 1 (D4): A perfect fourth above A3.

The overall harmonic content of the open strings (C, D, F, G, A) suggests a C Major 6/9 chord without the major third (E), or perhaps a C major pentatonic scale (C-D-E-G-A) with a flattened 3rd (F instead of E), making it lean towards C minor pentatonic extensions or a C suspended sound.

Open String Chords & Voicings

• C Power Chords (C5): Effortlessly achieved across the lowest five strings (C1-G1-C2-G2-C3). Barring these strings creates a monumental, thick C5 voicing.
• Open Sus Voicings: The combination of F3, A3, and D4 on the higher strings forms a Dsus4 chord. This allows for interesting open voicings and arpeggios that contrast with the heavy low end.
• Versatile Riffing: The drop-C-like nature of the lower strings, combined with the octave pairing, makes this tuning exceptionally good for fast, heavy riffs where the root and fifth are easily accessible.
• Extended Chords: By carefully fretting the higher strings, you can form open C-based chords with extensions like Cmaj9sus4 or C6/9 (omitting the E), leveraging the D, F, A notes.

How to Tune

To achieve the "C and G octave tuning" for your 8-string guitar, please follow these instructions for each string, from the thickest (8) to the thinnest (1):

• String 8 (Lowest): Tune to C1. You will need to tune this string down 1 semitones.
• String 7: Tune to G1. You will need to tune this string up 1 semitones.
• String 6: Tune to C2. You will need to tune this string up 1 semitones.
• String 5: Tune to G2. You will need to tune this string up 3 semitones.
• String 4: Tune to C3. You will need to tune this string up 3 semitones.
• String 3: Tune to F3. You will need to tune this string up 3 semitones.
• String 2: Tune to A3. You will need to tune this string up 2 semitones.
• String 1 (Highest): Tune to D4. You will need to tune this string up 3 semitones.

Important Note on String Tension: When making tuning changes, especially upward, always exercise caution. Each individual string movement in this tuning is within the generally safe limit of 4 semitones up or down. However, if your guitar was previously set up for a very different tuning or string gauge, you might consider having it professionally set up to ensure optimal playability and intonation for this specific "C and G octave tuning."

String 8 (Lowest): C1

String 7: G1

String 6: C2

String 5: G2

String 4: C3

String 3: F3

String 2: A3

String 1 (Highest): D4