Open A# Minor 7th / B Flat Minor 7th Tuning

This intriguing tuning, known as Open A# Minor 7th or B Flat Minor 7th, offers a unique and complex sonic landscape. While named as a minor 7th, a closer inspection reveals it's structured as an A# minor 7th flat 5 (A#ø7) chord across the open strings. This gives it a distinct melancholic yet sophisticated character, often associated with jazz, film scoring, and emotionally resonant musical contexts.

Technical Analysis

The open strings are tuned to A#2-F2-A#3-C#4-G#4-A#4. Let's analyze these notes relative to the root A#:

• 6th String (Low A#2): The root of the chord.
• 5th String (F2): This is the diminished 5th (or tritone) relative to A#. This F is what gives the tuning its half-diminished (ø7) quality, rather than a pure minor 7th (which would require an E# or F natural as a perfect 5th).
• 4th String (A#3): An octave of the root, reinforcing the fundamental.
• 3rd String (C#4): The minor 3rd, establishing the minor tonality.
• 2nd String (G#4): The minor 7th, adding the characteristic jazz/blues voicing.
• 1st String (High A#4): Another octave of the root, providing brightness and shimmer.

The overall intervallic structure from low to high is: Root, Diminished 5th, Octave, Minor 3rd, Minor 7th, Octave. This clearly spells out an A# half-diminished 7th chord (A#ø7). The repetition of the A# root across three strings provides a powerful and resonant foundation. The close proximity of the C# (m3), G# (m7), and A# (octave) on the top three strings makes for easy access to chord fragments and melodic ideas within the minor 7th framework.

Chords and Playability

• Open Strum: Strumming all open strings yields a full A#m7b5 (A# half-diminished 7th) chord, perfect for dramatic, melancholic, or jazzy passages.
• Barre Chords: The beauty of open tunings like this is the ease of transposing. A single finger barring all strings across any fret will produce the corresponding half-diminished 7th chord. For example, barring at the 1st fret gives you Bm7b5, at the 2nd fret Cm7b5, and so on. This makes playing complex chord progressions very accessible.
• Voicings: The unique string spacing also allows for interesting partial chords and arpeggios. Experiment with muting the 5th string (F2) to remove the b5, or combine the higher strings for pure minor 7th voicings. The top three strings (A#4, G#4, C#4) offer a compact A#m7 voicing.

How to Tune

To achieve the Open A# Minor 7th tuning, adjust your strings from standard tuning (EADGBe) as follows. Please exercise caution, especially with significant tuning changes, and consider a different string gauge if tuning outside of a 4-semitone range.

• 6th String (Low E): Tune the 6th string to A#2, tuning down 6 semitones. (Note: A string gauge change is advised for movements exceeding 4 semitones.)
• 5th String (A): Tune the 5th string to F2, tuning down 4 semitones.
• 4th String (D): Tune the 4th string to A#3, tuning down 4 semitones.
• 3rd String (G): Tune the 3rd string to C#4, tuning down 6 semitones. (Note: A string gauge change is advised for movements exceeding 4 semitones.)
• 2nd String (B): Tune the 2nd string to G#4, tuning down 3 semitones.
• 1st String (High E): Tune the 1st string to A#4, tuning down 6 semitones. (Note: A string gauge change is advised for movements exceeding 4 semitones.)

6th String: A2#
5th String: F2
4th String: A3#
3rd String: C4#
2nd String: G4#
1st String: A4#