The Open Amaj9 tuning transforms your guitar into a resonant soundscape, perfectly tailored for rich, jazz-infused chords and sophisticated harmonies. As its name suggests, this tuning allows you to strum an A Major 9th chord simply by playing all open strings, creating an instant lush and full sound.

Verbally, this tuning opens up a world of sonic possibilities. The disposition of notes across the fretboard facilitates the creation of beautiful, complex voicings with minimal effort. The original description highlights its suitability for producing "nice jazz chords" by simply barring a fret. This means if you bar the second fret, you'll immediately get a Bmaj9, and similarly for any other fret, offering an intuitive way to transpose major ninth chords across the neck. The full and warm sound makes it ideal for comping, fingerstyle jazz, or creating dreamy, ethereal soundscapes.

Technically, the open strings are tuned to A1-E2-A2-C4#-G4#-B3 (from low E to high E string). Analysing these notes relative to the root (A):

• 6th String (A1): Root
• 5th String (E2): Perfect 5th
• 4th String (A2): Octave (Root)
• 3rd String (C4#): Major 3rd
• 2nd String (G4#): Major 7th
• 1st String (B3): Major 9th

This precise arrangement forms a complete Amaj9 chord (A-C#-E-G#-B) spread across the open strings. The intervals between adjacent strings, from low to high, are: Perfect 5th (A-E), Perfect 4th (E-A), Major 3rd (A-C#), Perfect 5th (C#-G#), and Minor 3rd (G#-B). This combination of wide, open intervals followed by a tighter minor third at the top allows for both expansive harmony and delicate, close voicings. The low A-E-A foundation provides a solid, deep base, while the higher C#4, G#4, and B3 add the characteristic sparkle and complexity of a major ninth chord.

Beyond the open Amaj9, the consistent intervals mean that various other chord shapes become easily accessible. For instance, moving a single finger can transform the Amaj9 into related chords like Amaj7 by adjusting the highest string. Sliding a barred shape up and down the neck provides instant access to other Major 9th chords. The inherent jazz flavour of the Maj9 chord makes it a fantastic tuning for improvisation, offering a rich harmonic palette for soloing and melodic development. Minor 9th chords or dominant 7th chords are also often within easy reach by modifying just one or two notes, making this a highly versatile tuning for jazz, R&B, and contemporary music where rich harmonies are desired.

Tuning Notes for Open Amaj9

The Open Amaj9 tuning sets the strings to the following notes:

• 6th String: A1 (Lowest String)
• 5th String: E2
• 4th String: A2
• 3rd String: C4#
• 2nd String: G4#
• 1st String: B3 (Highest String)

How to Tune for Open Amaj9 from Standard Tuning (EADGBe)

This tuning requires significant adjustments from standard EADGBe tuning. Please note the substantial string movements; for optimal tone and string life, it is generally advised to consider using a different string gauge if tuning outside of a 4-semitone range (up or down) from its standard pitch. Tuning down typically benefits from heavier gauge strings, while tuning up may require lighter gauges.

• 6th String (Low E): From its standard E2 note, tune down 7 semitones to A1. (Movement: -7 semitones. A heavier string gauge is strongly advised for this significant drop to maintain tension and tone.)
• 5th String (A): From its standard A2 note, tune down 5 semitones to E2. (Movement: -5 semitones. A heavier string gauge is advised.)
• 4th String (D): From its standard D3 note, tune down 5 semitones to A2. (Movement: -5 semitones. A heavier string gauge is advised.)
• 3rd String (G): From its standard G3 note, tune down 6 semitones to C#3. (Movement: -6 semitones. A heavier string gauge is advised. Note: While following the 'tune down 6 semitones' instruction from standard G3 results in C#3, the final target note specified in the tuning definition is C4#, which is an octave higher. Please use a chromatic tuner to carefully reach C4# for this string. This might involve tuning up from G3, which could exceed safe tension limits for standard strings; consider a very light gauge if tuning up, or be cautious of string breakage.)
• 2nd String (B): From its standard B3 note, tune down 3 semitones to G#3. (Movement: -3 semitones. Note: While following the 'tune down 3 semitones' instruction from standard B3 results in G#3, the final target note specified in the tuning definition is G4#, which is an octave higher. Please use a chromatic tuner to carefully reach G4# for this string. This might involve tuning up from B3, which could exceed safe tension limits for standard strings; consider a very light gauge if tuning up, or be cautious of string breakage.)
• 1st String (High E): From its standard E4 note, tune down 5 semitones to B3. (Movement: -5 semitones. A heavier string gauge is advised.)