Tuning Analysis: Open Abm9 (with C Bass)

This intriguing tuning, named "Open Abm9", immediately presents a lush, complex minor 9th chord when all strings are played open. It offers a rich harmonic landscape, perfect for genres like jazz, blues, R&B, or any style seeking a sophisticated, melancholic, or moody texture. The arrangement of notes lends itself to easy exploration of complex voicings across the fretboard.

Technical Breakdown

The open strings are tuned to C2 - G#3 - B3 - D#4 - F#4 - A#4 (from low to high). When analyzed, these notes collectively form an Abm9 chord (Ab, Cb, Eb, Gb, Bb) with a crucial addition: a low C in the bass. This means the tuning can be technically described as an Abm9/C. The presence of all components for an Abm9 (Ab/G#, Cb/B, Eb/D#, Gb/F#, Bb/A#) confirms the tuning's name and stated intention to encompass Ab, Abm, Abm7, and Abm9 voicings.

The unique low C adds a deep, resonant foundation, making the open chord particularly full and evocative. This specific voicing gives the tuning a distinctive character that can be used for atmospheric pads, intricate chord melodies, or driving rhythmic patterns.

Open Chords & Accessibility

The primary open chord formed by this tuning is a magnificent Abm9. Its construction allows for easy transposition: by simply barring across any fret, you can effortlessly achieve the corresponding minor 9th chord. For example, barring at the 1st fret yields a C#m9 (Dbm9), at the 2nd fret a Dm9, and so on. This makes the tuning incredibly efficient for exploring and utilizing a vast array of minor 9th voicings with minimal effort, providing a consistent harmonic texture across the fretboard.

How to Tune Your Guitar

To achieve the "Open Abm9" tuning, follow these specific string adjustments:

• String 6 (Low E): Tune down 4 semitones to C2.
• String 5 (A): Tune down 1 semitone to G#3.
• String 4 (D): Tune up 1 semitone to D#4.
• String 3 (G): Tune down 1 semitone to F#4.
• String 2 (B): Keep as is; no change (0 semitones) at B3.
• String 1 (High E): Tune down 6 semitones to A#4.

Important Note on String Gauges: For significant string tension changes, particularly when tuning down by 4 or more semitones, or tuning up by 4 or more semitones, it is generally recommended to consider using a different gauge string. In this tuning, String 6 is tuned down 4 semitones and String 1 is tuned down 6 semitones, which means a lighter gauge string for the 6th and especially the 1st string might provide better playability and intonation, while also being safer for your guitar neck and string longevity.

String 6: C2

String 5: G3#

String 4: D4#

String 3: F4#

String 2: B3

String 1: A4#