The EBF#BEG#C# tuning for a 7-string guitar is a deeply resonant and highly unusual setup, leaning heavily into the "extended range" category. As described in its initial concept, it's a blend of "drop B but also somewhat drop E," which perfectly captures its extreme low end and unconventional structure. The lowest string is tuned to E1, a full octave below the standard low E of a 6-string guitar and even lower than a typical 7-string's low B. This plunges the instrument into truly subterranean sonic territory, ideal for heavy genres like progressive metal, doom, and djent, where immense depth and weighty riffs are paramount.

Technically, the open string notes are E1, B1, F#3, B2, E3, G#4, C#5. Strumming all open strings yields a rich Emaj6/9 chord (E - G# - B - C# - F#), creating a surprisingly bright and sophisticated harmonic texture despite the very low root. This allows for beautifully voiced open chords and arpeggios that would be impossible in standard tunings.

Technical Analysis:

The intervals between strings are highly unconventional, moving beyond typical consistent intervals (like perfect fourths or fifths) found in standard or common drop tunings:

• String 7 (E1) to String 6 (B1): A perfect 5th (E to B). This forms a classic power chord foundation with the lowest strings.
• String 6 (B1) to String 5 (F#3): A massive leap of an octave and a perfect 5th (B to F#). This creates a very wide interval and a distinct shift in register.
• String 5 (F#3) to String 4 (B2): A descending perfect 4th (F# down to B). This is an unusual step, where the 4th string is lower than the 5th string, requiring careful fretboard navigation.
• String 4 (B2) to String 3 (E3): A perfect 4th (B to E).
• String 3 (E3) to String 2 (G#4): An octave and a major 3rd (E to G#), another significant leap in pitch.
• String 2 (G#4) to String 1 (C#5): A perfect 4th (G# to C#).

The presence of E1 and B1 at the bottom provides a solid foundation for deep power chords. The repeated B notes (B1 on string 6, B2 on string 4) and E notes (E1 on string 7, E3 on string 3) offer convenient octaves and unisons across different registers, allowing for massive, layered sounds. For example, barring across the lowest strings (7 and 6) can easily form power chords (e.g., E5 on the open strings). The lowest E1 string is a natural for single-finger "drop" chords, where one finger frets the low E, and other fingers form chord shapes on the higher strings. The open strings themselves form an Emaj6/9 chord, which is a rich, open voicing that can be used as a harmonic bed or for arpeggiated figures.

This tuning's wide, non-linear intervals will present a unique challenge and opportunity for players, demanding a deep understanding of the fretboard to navigate. It discourages typical scale and chord shapes but opens the door for highly specific and unique voicings. Given the extreme downtuning of most strings (especially the lowest two), using a heavier gauge string set is essential to maintain playable tension and intonation. This tuning is designed for adventurous players seeking new sonic textures and immense low-end power.

How to Tune:

• String 7 (Lowest E1): To reach E1, tune this string down 7 semitones. This is a significant drop; a heavier gauge string is strongly advised.
• String 6 (B1): To reach B1, tune this string down 5 semitones. A heavier gauge string is advised.
• String 5 (F#3): To reach F#3, tune this string down 3 semitones.
• String 4 (B2): To reach B2, tune this string down 3 semitones.
• String 3 (E3): To reach E3, tune this string down 3 semitones.
• String 2 (G#4): To reach G#4, tune this string down 3 semitones.
• String 1 (Highest C#5): To reach C#5, tune this string down 3 semitones.

String 7 (Lowest): E1

String 6: B1

String 5: F#3

String 4: B2

String 3: E3

String 2: G#4

String 1 (Highest): C#5