This Guitar tuning, aptly named Gadd9, is a unique and resonant variation that diverges significantly from standard tuning. As described, it forms an open Gadd9 chord when strummed openly, providing an immediate, rich harmonic foundation.

Verbal Analysis

The most striking feature of the Gadd9 tuning is the foundational drone created by the lowest three strings, all tuned to A (A1, A2, A2). This triple-A configuration gives the tuning immense depth and resonance, establishing a powerful low end that can be felt as much as heard. When strummed open, the full chord (A-A-A-G-B-D) sounds like a rich Gadd9 chord with an A in the bass, specifically Gadd9/A. This creates a full, vibrant, and somewhat expansive sound, perfect for ambient textures, folk, or rock where a constant, deep harmonic bed is desired. The sound is bright yet grounded, making it highly evocative and inspiring for songwriting.

Technical Analysis

• Overall Structure: The tuning is A-A-A-G-B-D, from the 6th to the 1st string.
• Low End Innovation: The unconventional unison tuning of the 5th and 4th strings to A2, alongside the 6th string tuned to A1 (an octave lower), is a defining characteristic. This provides a massive, sustained low-end drone.
• Mid-Range Stability: The 3rd (G3) and 2nd (B3) strings retain their standard tuning relationship, creating a familiar G-B interval which is the foundation of a G major triad.
• High End Variation: The 1st string is tuned down to D4, completing the Gadd9 chord (G-B-D-A) over the A drone.
• Harmonic Content: The open strings contain the notes A, G, B, D. This collection forms a Gadd9 chord (G-B-D-A) with the low A serving as a pedal tone, or as an inversion (Gadd9/A).

Open and Reachable Chords

This tuning is designed to sound complete and chordal when played open, providing an instant Gadd9/A. This makes it ideal for songs in the key of G major, A minor (specifically A Dorian due to the prominent A-D-G relationship), or even D major. The triple A drone invites experimentation with single-finger melody lines or two-finger chord shapes on the higher strings. Barre chords become particularly interesting; a single finger across a fret on the 5th, 4th, 3rd, 2nd, and 1st strings will yield major or minor chords with the low A drone always present. Sliding shapes up and down the neck while maintaining the open A string can create unique, evolving harmonies. The close proximity of the A notes makes for powerful octaves and fifths when played on the lower strings, while the G-B-D provides a familiar major triad structure on the higher strings.

How to Tune

To achieve the Gadd9 tuning from standard E-A-D-G-B-E tuning, follow these specific string adjustments:

• 6th String (Low E): Tune down 7 semitones to A1. (Note: A change of -7 semitones is significant; consider a heavier gauge string if this tuning is to be permanent to maintain proper tension and tone.)
• 5th String (A): Keep as is; no change (0 semitones). It remains A2.
• 4th String (D): Tune down 5 semitones to A2. (Note: A change of -5 semitones is significant; consider a heavier gauge string if this tuning is to be permanent to maintain proper tension and tone.)
• 3rd String (G): Keep as is; no change (0 semitones). It remains G3.
• 2nd String (B): Keep as is; no change (0 semitones). It remains B3.
• 1st String (High E): Tune down 2 semitones to D4.

Important Note: Significant changes in string tension, particularly tuning down 5 or more semitones, can affect string stability and intonation. For tunings involving changes greater than 4 semitones (up or down), using a different gauge string set is often recommended for optimal playability and to prevent string damage.

The notes for the Gadd9 tuning, from the thickest (6th) string to the thinnest (1st) string, are:

• 6th String: A1
• 5th String: A2
• 4th String: A2
• 3rd String: G3
• 2nd String: B3
• 1st String: D4