The 'Open D Augmented 5th Sus Tuning' is a highly unconventional and intriguing guitar tuning that deviates significantly from standard open tunings. At first strum, it presents a complex and somewhat dissonant sound due to the unique interval relationships, particularly the prominent A# (Bb) on the 5th string. This tuning is not designed for easy, familiar chord shapes but instead invites experimentation and a fresh approach to the fretboard. It holds great potential for musicians exploring genres like experimental rock, blues (with its minor 6th feel from the Bb), jazz fusion, or even soundtrack composition, offering a palette of unique voicings and textures. It will challenge your muscle memory but reward you with distinctive sonic landscapes.

Technical Analysis

This tuning transforms your guitar into D2 A#3 D3 G3 A3 E4 (D Bb D G A E). Analyzing the intervals from the low D string (D2):

• The 6th string is tuned to D2 (Root).
• The 5th string is A#3 (Bb), which is an Augmented 5th or Minor 6th interval above the low D. This is the most striking feature of the tuning, introducing a strong tension or bluesy character.
• The 4th string is D3, an octave above the 6th string.
• The 3rd string is G3, a Perfect 4th above the low D.
• The 2nd string is A3, a Perfect 5th above the low D.
• The 1st string is E4, a Major 9th (or Major 2nd up an octave) above the low D.

The combination of D-G-A-E on strings 6, 4, 3, 2, 1 (ignoring the A#) suggests a Dsus4(add9) tonality. However, the inclusion of the A# (Bb) on the 5th string adds a distinctive and often dissonant color that pushes the tuning beyond simple suspended harmony. Open chords are not readily apparent in a traditional sense. Strumming all open strings will produce a cluster chord D-A#-D-G-A-E. Rather than typical open chords, this tuning is more conducive to specific melodic lines, drones, or exploring new chord shapes that leverage the unique intervals, especially the prominent A#. Exploring chord shapes around the 3rd or 5th frets, or utilizing a slide, could yield particularly interesting harmonic possibilities in this tuning.

How to Tune Your Guitar

To tune your guitar to the 'Open D Augmented 5th Sus Tuning' (D A# D G A E), follow these precise string adjustments from standard EADGBe tuning. Remember to tune slowly and carefully, especially with larger movements.

• 6th String (Low E): Tune down 2 semitones to reach D2.
• 5th String (A): Tune up 1 semitone to reach A3#.
• 4th String (D): Keep as is; no change (0 semitones) from standard D3.
• 3rd String (G): Keep as is; no change (0 semitones) from standard G3.
• 2nd String (B): Tune down 2 semitones to reach A3.
• 1st String (High E): Keep as is; no change (0 semitones) from standard E4.

Important Tuning Note: Extreme care should be taken when tuning strings significantly. For movements exceeding 4 semitones (either up or down), it is generally advisable to consider using a different string gauge to avoid excessive tension on the neck or potential string breakage. While most movements in this tuning are minor, always listen to your guitar and proceed with caution.