This is the Open F6/9 tuning. It has a rich harmonic texture, sounds dreamy and lush, and is just perfect for shoegaze and other atmospheric genres.

Technical Analysis:

The open strings are tuned to F2, A2, C3, D3, G3, A3 (from low E to high E string positions). This configuration creates a resonant F Major 6/9 chord when strummed open. Let's explore its harmonic makeup:

• F (String 6): This establishes the root of the chord.
• A (String 5): Provides the Major 3rd of the F chord.
• C (String 4): Delivers the Perfect 5th, solidifying the F Major triad.
• D (String 3): Adds the Major 6th, giving the tuning its distinctive '6' character.
• G (String 2): Introduces the Major 9th (a Major 2nd an octave up), completing the '9' aspect of the chord.
• A (String 1): Reinforces the Major 3rd an octave higher, adding brightness and sustain to the chord.

The open tuning is inherently a beautiful, complex Fmaj6/9 chord. This makes it incredibly easy to achieve lush, full-bodied sounds without complex fingerings. Barring across any fret will instantly produce other Xmaj6/9 chords (e.g., barring at the 1st fret gives F#maj6/9, 2nd fret for Gmaj6/9, and so on), providing a consistent harmonic landscape across the fretboard.

Due to the significant down-tuning on several strings (especially the 1st, 2nd, and 3rd strings which are dropped by 7, 4, and 5 semitones respectively), it's highly recommended to consider using heavier gauge strings for optimal tension, intonation, and to prevent the strings from feeling too loose or 'floppy'. This will ensure a more stable and satisfying playing experience.

How to Tune to Open F6/9:

To achieve the Open F6/9 tuning, adjust each string from standard E standard (E-A-D-G-B-E) as follows. Pay close attention to the direction and number of semitones for each string.

• String 6 (Low E String): Tune up 1 semitones from E to F2. (Generally safe for most string gauges, but always tune carefully.)
• String 5 (A String): Keep as is; no change (0 semitones) from A to A2.
• String 4 (D String): Tune down 2 semitones from D to C3.
• String 3 (G String): Tune down 5 semitones from G to D3. Warning: This is a significant drop in tension. For optimal playability and intonation, a heavier gauge string is strongly advised for this string.
• String 2 (B String): Tune down 4 semitones from B to G3. Warning: This is a considerable drop in tension. A heavier gauge string is recommended to maintain good tension and tone.
• String 1 (High E String): Tune down 7 semitones from E to A3. Warning: This is a very substantial drop in tension. A much heavier gauge string is strongly recommended for this string to prevent it from being too loose and to ensure proper intonation.

Always tune slowly and check your intonation, especially after making large adjustments to string tension. If you plan to use this tuning frequently, consider setting up your guitar with appropriate string gauges.