The D modal tuning, as its name suggests and its description implies ('good for rock'), is a deeply resonant and powerful setup for the guitar. Its open strings ring out to D-A-D-G-G-D, immediately presenting a full-bodied Dsus4 chord. This configuration creates a heavy, driving sound, perfect for genres demanding a strong, sustained presence and a unique tonal palette.

Technical Analysis:

• Root Note Focus: With D as the foundational note on both the 6th (low) and 1st (high) strings, this tuning establishes a strong emphasis on the key of D. The repeated D notes across octaves reinforce a powerful, drone-like quality.
• Modal Flavor: The inclusion of G (a perfect 4th relative to D) on both the 3rd and 2nd strings is a defining characteristic. This G-G unison adds a distinct modal flavor, leaning towards D Dorian or D Mixolydian scales, offering a versatile range for melodic and harmonic exploration beyond typical major/minor frameworks.
• Intervals: From low to high, the intervals relative to the root D are: Root (D), Perfect 5th (A), Octave (D), Perfect 4th (G), Perfect 4th (G), Octave (D). The distinct unison of the G3 notes on the 3rd and 2nd strings is a unique feature that allows for rich, ringing harmonies and thick voicings.

Chords and Playability:

• Open Voicing: Strumming all open strings yields a powerful Dsus4 chord (D-G-A). This provides an instant, resonant harmony, ideal for expansive intros, robust rhythmic patterns, or as a drone.
• Simplified Power Chords: The D-A-D configuration on the lower three strings (6th, 5th, 4th) significantly simplifies playing power chords. Barring across these strings at any fret will produce a powerful root-fifth-octave shape, making heavy riffs and chord changes quick and easy, which is highly advantageous for rock and metal styles. For example, a C5 power chord can be played by simply barring the 6th, 5th, and 4th strings at the 8th fret (C-G-C).
• Unique Unison & Drones: The G-G unison on the 3rd and 2nd strings offers interesting drone possibilities and allows for thick, sustained notes that can add depth and texture to riffs and melodies. This makes shaping chords around these two strings particularly distinctive, and they can be used effectively as a constant tonal center.
• New Chord Voicings: While standard barre chord shapes will require adaptation due to the altered string intervals (especially the G-G unison and the dropped high E string), this tuning opens up new, unique voicings. It encourages players to explore unconventional chord shapes that utilize the open strings for a ringing, resonant sound.

Overall, the "D modal" tuning is an excellent choice for guitarists seeking a weighty, open sound with significant modal versatility. It is particularly well-suited for rock, metal, and ambient genres where powerful, resonant chords, simplified power chords, and distinctive open-string voicings are desired.

Current Tuning Notes:

String 6 (Low E): D2
String 5 (A): A2
String 4 (D): D3
String 3 (G): G3
String 2 (B): G3
String 1 (High E): D4

How to Tune:

To achieve the D modal tuning from a standard E A D G B E setup, follow these specific string adjustments:

• String 6 (Low E): Tune down 2 semitones from its standard E2 pitch to D2.
• String 5 (A): Keep as is; no change (0 semitones). The note remains A2.
• String 4 (D): Keep as is; no change (0 semitones). The note remains D3.
• String 3 (G): Keep as is; no change (0 semitones). The note remains G3.
• String 2 (B): Tune down 4 semitones from its standard B3 pitch to G3. Note of Caution: Tuning down 4 semitones is a significant drop in pitch. If you experience excessive string looseness, buzzing, or difficulty intonating, consider using a heavier gauge string for this particular string to ensure optimal playability and tone.
• String 1 (High E): Tune down 2 semitones from its standard E4 pitch to D4.

Always tune carefully, using a reliable digital tuner to ensure accuracy. Pay close attention to string tension, especially when making larger semitone adjustments.