Verbal Analysis

The Open A#9 tuning (also known as Open Bb9) creates an exceptionally rich and sophisticated sonic landscape. It immediately evokes a jazzy, full-bodied chord, making it ideal for genres like jazz, fusion, R&B, neo-soul, or even experimental soundscapes where complex harmony is desired. The open strings offer a beautiful, resonant chord that sounds complete and inspiring on its own. For slide guitarists, this tuning provides a lush foundation for expressive melodies and glissandos. While not a common tuning, its unique character invites exploration and could easily become a signature sound for adventurous players.

Technical Analysis

This tuning comprises the notes F2, A#3, D3, G#4, C4, F4 (low to high). When played open, these strings collectively form an A# Major 7th chord (Bb Major 7th) with an added 9th, voiced over a low F. Specifically, the notes represent:

• String 6 (F2): The Perfect 5th below the root A#.
• String 5 (A#3/Bb3): The Root.
• String 4 (D3): The Major 3rd.
• String 3 (G#4/Ab4): The Minor 7th.
• String 2 (C4): The Major 9th (equivalent to a Major 2nd).
• String 1 (F4): The Perfect 5th.

The result is a Bbmaj7(9)/F chord, which is harmonically dense and provides a strong foundation for improvisation within the key of A#/Bb. The wide range of pitches across the strings, particularly the high G#4, offers unique melodic possibilities. While standard chord shapes will be entirely reconfigured, barre chords will likely yield various voicings of A#maj7(9) or closely related extended chords up the fretboard.

Chords within Reach

Beyond the open A#maj7(9)/F, this tuning facilitates rich voicings of A# (Bb) major family chords. Simple one or two-finger additions can easily create sus4, add11, or other extended harmonies around the root. Due to the high tension on some strings, experimenting with lighter gauge strings might be beneficial for playability and string longevity. Open minor chords are not directly available but can be formed by fretting.

Tuning Notes

The notes for Open A#9 tuning are as follows, from the lowest (thickest) string to the highest (thinnest) string:

String 6: F2
String 5: A3#
String 4: D3
String 3: G4#
String 2: C4
String 1: F4

How to Tune

To achieve the Open A#9 tuning, starting from standard EADGBe tuning, make the following adjustments to each string:

• String 6 (Low E): Tune up 1 semitone to F.
• String 5 (A String): Tune up 1 semitone to A#.
• String 4 (D String): Keep as is; no change (0 semitones) to D.
• String 3 (G String): Tune up 1 semitone to G#. CAUTION: While this instruction states a 1 semitone increase based on the movement, the target note G4# (G sharp 4) is an octave and a semitone (13 semitones) higher than a standard G3. Tuning up by more than 4 semitones can put excessive tension on the string and neck; a lighter gauge string is strongly advised for this string to prevent breakage and potential neck damage.
• String 2 (B String): Tune up 1 semitone to C.
• String 1 (High E String): Tune up 1 semitone to F.