This tuning, aptly named "Opeth Open G Minor 9 (7-String)", is crafted to immerse you in the dark, progressive soundscapes synonymous with the iconic band Opeth. It provides a rich, resonant low end combined with complex harmonic possibilities, perfect for heavy riffs, atmospheric passages, and intricate chord voicings.

Technical Analysis

• Instrument Type: 7-String Guitar.
• Open Notes: The tuning from low to high is G1-D2-A2-D3-F3-A3-D4.
• Harmonic Structure: At its core, this tuning presents a G minor 9th type of voicing. It features the root (G), perfect fifth (D), major ninth (A), and minor seventh (F), often without a specific third. This omission creates an open, ambiguous, and somewhat suspended quality, characteristic of progressive and heavy metal, offering a dark and expansive harmonic palette.
• Chordal Voicings:
  • The lowest two strings (G1-D2) form a powerful G5, providing a solid, rumbling foundation for heavy riffs.
  • The sequence of D-A-D on strings 6, 5, and 4 provides a strong open D power chord, perfect for drone notes.
  • The D-A-D-F-A-D arrangement on strings 6-1 allows for easy access to dark, melancholic D minor 7 (sus2) voicings, and facilitates broad, arpeggiated figures across the neck.
  • The overall tuning emphasizes fifths, fourths, and specific intervals (minor 7th, major 9th), making it ideal for creating full, dissonant, or suspended chords with minimal effort.
• Playability: The repeated D and A notes across various strings facilitate easy drone notes and power chords. This structure simplifies the construction of heavy, chugging riffs and wide, open arpeggios, while the heavily 'dropped' nature of many strings lends itself to a looser feel and profoundly deep tones.

Notes and 'How to Tune'

To achieve the "Opeth Open G Minor 9 (7-String)" tuning, follow these precise adjustments from standard 7-string tuning (B-E-A-D-G-B-E), tuning each string to its specified note:

• 7th String (Lowest B String to G1): Tune down 4 semitones. (Note: Tuning down 4 semitones is significant; a heavier gauge string is advised for optimal tension and tone at G1.)
• 6th String (E String to D2): Tune down 2 semitones.
• 5th String (A String to A2): Keep as is; no change (0 semitones).
• 4th String (D String to D3): Keep as is; no change (0 semitones).
• 3rd String (G String to F3): Tune down 2 semitones.
• 2nd String (B String to A3): Tune down 2 semitones.
• 1st String (Highest E String to D4): Tune down 2 semitones.

These precise adjustments will transform your 7-string guitar into a powerful sonic tool for progressive and heavy music, delivering the characteristic depth and harmonic richness of the Opeth style.