This is an exhilarating open tuning for your Guitar, officially known as Open A#m9, also frequently referred to as B flat minor 9th. As its name suggests, this tuning immediately presents a rich A# minor 9th chord when strummed open, enveloping your sound in a sophisticated and melancholic harmony. It's a fantastic choice for players exploring jazz, blues, contemporary R&B, or any genre where complex, emotive chords are desired. The inherent tension and release of the minor 9th interval are readily available, making for quick access to evocative voicings.

Technical Analysis

The open strings are tuned as follows, from the lowest (6th) to the highest (1st) string:

• String 6: F2 (Low F)
• String 5: A#3 (A-sharp)
• String 4: C#4 (C-sharp)
• String 3: G#4 (G-sharp)
• String 2: A#4 (A-sharp)
• String 1: C4 (Middle C)

When played open, these notes – F, A#, C#, G#, A#, C – collectively form an A#m9 (A# minor 9th) chord, specifically an inversion with F as the lowest note (A#m9/F). The chord consists of the root (A#), minor third (C#), perfect fifth (F), minor seventh (G#), and the major ninth (C). The strategic placement of A# on two different strings (5th and 2nd) and C# on the 4th string allows for powerful, thick chord voicings and drone possibilities. This arrangement provides a strong tonal center with accessible harmonic extensions.

Chordal Opportunities

The beauty of this open tuning is its immediate playability. Strumming all open strings delivers a full A#m9/F chord, providing a rich, complex harmonic starting point. Due to the consistent intervallic structure, you can easily create new minor 9th chords by simply barring across any fret. For example:

• Barre at the 1st fret yields a Bm9/F# chord.
• Barre at the 3rd fret yields a C#m9/G# (or Dbm9/Ab) chord.

Beyond simple barring, the tuning's internal logic makes it intuitive to find related chords. Minor 7th chords are readily available by omitting the 1st string. Experiment with single-finger movements on the higher strings to discover suspended chords or dominant 7th voicings that resolve beautifully back to the minor 9th.

How to Tune to Open A#m9

To achieve this tuning from standard E A D G B E, carefully adjust each string as follows:

• 6th String (Low E): Tune up 1 semitones from E2 to F2.
• 5th String (A): Tune up 1 semitones from A3 to A#3 (B-flat).
• 4th String (D): Tune down 1 semitones from D4 to C#4 (D-flat).
• 3rd String (G): Tune up 1 semitones from G4 to G#4 (A-flat).
• 2nd String (B): Tune down 1 semitones from B4 to A#4 (B-flat).
• 1st String (High E): Tune down 4 semitones from E4 to C4 (Middle C). Caution: This is a significant drop. If you frequently use this tuning, consider using a lighter gauge string for your 1st string to prevent excessive slack and ensure optimal tone.

Always tune carefully and check intonation after making significant changes, especially when tuning strings up or down by multiple semitones.

String 6 (low E string): F2
String 5 (A string): A#3
String 4 (D string): C#4
String 3 (G string): G#4
String 2 (B string): A#4
String 1 (high E string): C4