Verbal Analysis:

The "Open F6/9" tuning for an 8-string guitar, as its name suggests, creates a rich and resonant F6/9 chord when strummed open. This tuning builds upon a robust low F foundation, delivering a full, thick sound that's ideal for genres requiring heavy, yet harmonically complex, textures such as progressive metal, djent, or atmospheric rock. The creator notes it's a variation on a Josh Travis tuning, emphasizing a desire for a high D instead of E, hinting at a connection to a Drop C feel. This suggests a tuning designed for deep, impactful riffs with melodic possibilities on the higher strings, offering a blend of aggressive power and sophisticated harmony.

Technical Analysis:

The open notes are F1-C2-G2-C3-F3-G3-A3-D4. Let's break down the intervals relative to the lowest F (F1):

• F1 (Root): The foundational low end.
• C2 (Perfect 5th): Reinforces the F power chord.
• G2 (Major 9th/2nd): Adds a suspended quality or a rich extension.
• C3 (Perfect 5th, octave higher): Further strengthens the F chord.
• F3 (Octave): Provides another octave of the root.
• G3 (Major 9th/2nd, octave higher): Continues the extended harmony.
• A3 (Major 3rd): Establishes the F chord as a Major quality.
• D4 (Major 6th): Completes the F6/9 chord voicing.

This tuning effectively spells out an F Major triad (F-A-C) with the added 2nd/9th (G) and 6th (D). The multiple Fs, Cs, and Gs create a dense, resonant harmonic series. The presence of the high D4 (a semitone lower than a standard high E) likely facilitates specific melodic patterns or gives a desired tonal character, possibly connecting to the "Drop C" feel the creator mentioned, perhaps by allowing open string harmony or common shapes familiar from that tuning.

Open & Accessible Chords:

• Open Strum: The most prominent feature is the full F6/9 chord (F-C-G-C-F-G-A-D) available by simply strumming all open strings. This provides a rich, complex harmonic starting point.
• Power Chords: Due to the multiple Fs and Cs, power chords are incredibly easy to form. Simply barring the lowest three or four strings at any fret will yield powerful, resonant chords rooted on the 8th string. The F-C-G-C-F interval structure on the lower strings makes for very thick power chords.
• Suspended Chords: The abundant G notes (M9/2nd) mean suspended 2nd chords are readily available by omitting the A3, or simply by focusing on the lower strings.
• Melodic Runs: The higher strings (G3, A3, D4) offer interesting melodic possibilities, and their relationship (G-A is M2, A-D is P4) can facilitate open-string harmonies or specific scale fragments.

How to Tune:

To achieve the "Open F6/9" tuning from a standard 8-string setup, follow these string adjustments:

• 8th String (Lowest): Tune down 1 semitone to F1.
• 7th String: Tune up 1 semitone to C2.
• 6th String: Tune up 3 semitones to G2. Please take care when tuning up 3 semitones to avoid excessive string tension.
• 5th String: Tune up 3 semitones to C3. Please take care when tuning up 3 semitones to avoid excessive string tension.
• 4th String: Tune up 3 semitones to F3. Please take care when tuning up 3 semitones to avoid excessive string tension.
• 3rd String: Keep as is; no change (0 semitones) at G3.
• 2nd String: Tune down 2 semitones to A3.
• 1st String (Highest): Tune down 2 semitones to D4.

Note: For significant changes (tuning down more than 4 semitones or up more than 4 semitones from your current gauge's intended tension), a different string gauge may be advised to maintain optimal playability and string life. The 3-semitone increases here should be approached with care.

Here are the open notes for the "Open F6/9" tuning:

8th String (Lowest): F1

7th String: C2

6th String: G2

5th String: C3

4th String: F3

3rd String: G3

2nd String: A3

1st String (Highest): D4