The Open Dsus4 tuning, often simply referred to as Dsus4, is a highly versatile and resonant tuning, particularly celebrated for its modal possibilities and open, atmospheric soundscapes. As its name suggests, this tuning immediately presents a D suspended 4th chord when strummed open, giving it a characteristic yearning or unresolved quality that lends itself beautifully to folk, blues, and ambient music, as well as being a favorite for slide guitarists.

Technically, the open string notes are configured as D2-G2-D3-D3-G3-D4 (low to high). This arrangement provides a powerful D root note across multiple octaves, along with the characteristic G (the perfect fourth) which defines the 'sus4' quality. The striking feature here is the unison of the 3rd and 4th strings (both D3), which adds a unique thickness and sustain, and the repeated G on the 5th and 2nd strings, reinforcing the suspended harmony.

This tuning makes a variety of chords readily accessible. Strumming all open strings delivers a rich Dsus4. A single barre across any fret will instantly give you a suspended 4th chord based on that fret's root note (e.g., barring at the 2nd fret creates an Esus4). Due to the inherent openness, it's relatively easy to modify the open Dsus4 into a D Major by fretting the 3rd string at the 2nd fret (F#), or a D Minor by fretting the 2nd string at the 3rd fret (F). The drone-like quality of the D and G notes makes it an excellent canvas for melodic improvisation and creating expansive soundscapes without complex fingering.

How to Tune (from Standard E-A-D-G-B-E)

• 6th String (Low E): Tune down 2 semitones to D2.
• 5th String (A): Tune down 2 semitones to G2.
• 4th String (D): Keep as is; no change (0 semitones) to D3.
• 3rd String (G): Tune down 5 semitones to D3. Note: A drop of 5 semitones is significant. Consider a heavier gauge string if you frequently use this tuning to maintain optimal tension and tone.
• 2nd String (B): Tune down 4 semitones to G3. Note: A drop of 4 semitones is considerable. Using a slightly heavier gauge string is recommended for better tension and playability.
• 1st String (High E): Tune down 2 semitones to D4.

6th String: Tuned to D2 (Lowest string)

5th String: Tuned to G2

4th String: Tuned to D3

3rd String: Tuned to D3

2nd String: Tuned to G3

1st String: Tuned to D4 (Highest string)