The tuning you've provided is named "F# Octave tuning" and is described as "The 7-string equivalent of BADGBE." This description is accurate in terms of relative intervals: like BADGBE (B-A-D-G-B-E), the lowest string (F#) is tuned a whole step down from the adjacent string (E), and the remaining intervals (E-A, A-D, D-G, G-B, B-E) mirror the standard EADGBE intervals. The actual open string notes are F#2, E2, A2, D3, G3, B3, E4. This setup essentially gives you standard EADGBE tuning on the top six strings (E2-E4) with the addition of a very low F#2 on the 7th string.

Verbal Analysis:

This is a powerful and versatile 7-string tuning, offering the familiar ground of standard EADGBE for the higher six strings while significantly expanding the lower register with an F#2. This deep, resonant F# opens up new possibilities for heavy genres like metal, djent, and progressive rock, allowing for crushing low-end riffs and extended melodic range. The "octave" in the name might refer to the broad range covered by the tuning or perhaps the deep, resonant F# serving as a foundational octave. The F# provides a deep, growling foundation that can be used for dissonant intervals against the E string, or as a strong root for power chords and intricate bass lines.

Technical Analysis:

The tuning layout for the 7-string guitar is F#2 E2 A2 D3 G3 B3 E4.

• String 7 (F#2): This is the defining feature, extending the range significantly below a standard 7-string's low B. The interval between the 7th string (F#) and 6th string (E) is a Major 7th up (or a minor 2nd down), providing a tense, dissonant interval when played open together, or a strong foundation when used for roots of chords.
• Strings 6-1 (E2 A2 D3 G3 B3 E4): These strings are tuned identically to standard EADGBE. This means all familiar chords, scales, and arpeggios typically played on a 6-string in standard tuning can be directly applied to these strings without re-learning fingerings. This makes the tuning highly approachable for players accustomed to 6-string standard tuning.

While the open strings as a whole don't form a conventional single major or minor chord, the presence of standard EADGBE on the top six strings means all common open chords are readily available on those strings (e.g., E major, A minor, G major, C major, D major, etc.). The F# on the 7th string can then be utilized as a powerful root for F# power chords (F#5, F#sus2) or as a complementary bass note to chords played on the higher strings. For instance, playing an Em chord on strings 1-6 while also ringing the open F# creates a distinctive, dark F#sus2/Em voicing or an Em(addF#) depending on context. This tuning also lends itself well to single-note riffing and chugging on the lower strings due to the deep F# and its interval relationship with the E string.

How to Tune:

To achieve this F# Octave tuning, adjust your strings as follows. Please exercise caution when tuning, especially with significant semitone changes:

• String 7 (Lowest String): Tune down 5 semitones to F#2. Note: Tuning down 5 semitones is a substantial change. For optimal string tension and tone, especially if your guitar was previously in a much higher tuning, a heavier gauge string is strongly advised.
• String 6: Keep as is; no change (0 semitones) to E2.
• String 5: Keep as is; no change (0 semitones) to A2.
• String 4: Keep as is; no change (0 semitones) to D3.
• String 3: Keep as is; no change (0 semitones) to G3.
• String 2: Keep as is; no change (0 semitones) to B3.
• String 1 (Highest String): Keep as is; no change (0 semitones) to E4.

String 7: F2#

String 6: E2

String 5: A2

String 4: D3

String 3: G3

String 2: B3

String 1: E4