The Open Dmaj9 tuning is a rich and sophisticated sound that immediately brings a sense of lushness and melodic possibility. As described by its creator, this tuning evolved from an Open Dmaj7sus2 tuning (DADAC#E) with influences from Weatherday, suggesting a unique blend of progressive, indie, and perhaps emo-tinged sonic landscapes. It's perfectly suited for atmospheric passages, intricate arpeggios, and compositions demanding a full, extended harmonic palette.

Technical Analysis

The Open Chord & Accessible Voicings

The most striking feature is that simply strumming all open strings yields a beautiful D Major 9th (Dmaj9) chord. The notes, from low to high, are D2, F3#, C4#, A3, C5#, E4. When arranged chromatically and octave-normalized, these notes are D - F# - A - C# - E, clearly forming a Dmaj9. This inherent harmony makes the tuning incredibly inspiring, allowing for instant gratification with full, complex chords.

Beyond the open Dmaj9, this tuning facilitates easy access to a variety of related chords:

• D Major Triad: By simply muting or avoiding the C# and E notes on the higher strings, you can easily imply a D major triad (D-F#-A).
• D Major 7th: The C# is present on both the 4th and 2nd strings, making Dmaj7 shapes (D-F#-A-C#) readily available with minimal effort.
• Parallel Major 9ths: Sliding a simple bar shape up and down the neck will immediately yield parallel Major 9th chords, providing a quick way to transpose the rich open sound. For instance, barring all strings at the 2nd fret would give you an Emaj9.
• Arpeggios: The wide string intervals (e.g., F# to C# is a perfect 5th, C# to A is a minor 6th, A to C# is a major 3rd, C# to E is a minor 3rd) offer unique opportunities for wide, sweeping arpeggios that would be challenging in standard tuning.

String Tension & Gauge Advisory

When tuning your guitar to Open Dmaj9, please note the following string movements from standard EADGBe tuning:

• The 6th string (Standard E2) is tuned down 2 semitones to D2.
• The 5th string (Standard A2) is tuned down 3 semitones to F3#.
• The 4th string (Standard D3) is tuned down 1 semitone to C4#.
• The 3rd string (Standard G3) is tuned up 2 semitones to A3.
• The 2nd string (Standard B3) is tuned up 2 semitones to C5#.
• The 1st string (Standard E4) remains as is at E4.

While most movements are within a safe range, tuning the 3rd (G) and 2nd (B) strings up by 2 semitones each does increase their tension. This is generally acceptable for standard string gauges. However, for movements exceeding 4 semitones up or down, a different gauge string is often advised. In this specific tuning, all movements are within or below this threshold, so your current string set should be suitable, though always monitor string tension and intonation closely after tuning.

How to Tune

Here are the specific instructions to tune your guitar from standard EADGBe to Open Dmaj9:

• String 6 (Low E): Tune down 2 semitones to reach D2.
• String 5 (A): Tune down 3 semitones to reach F#3.
• String 4 (D): Tune down 1 semitone to reach C#4.
• String 3 (G): Tune up 2 semitones to reach A3.
• String 2 (B): Tune up 2 semitones to reach C#5.
• String 1 (High E): Keep as is; no change (0 semitones) to remain at E4.

Here are the notes for each string in the Open Dmaj9 tuning, from thickest (6th) to thinnest (1st):

• 6th String: D2
• 5th String: F3#
• 4th String: C4#
• 3rd String: A3
• 2nd String: C5#
• 1st String: E4