This intriguing tuning, named "Open Ab Major / C," transforms your guitar into a resonant soundscape, offering unique harmonic possibilities. From the 5th string to the 1st, it beautifully lays out an Ab Major chord (Ab-Eb-Ab-C-Eb). With the addition of a profound low C on your 6th string, this tuning establishes a powerful foundation, essentially presenting an Ab Major chord with C in the bass. This creates a rich, complex sonority, leaning into C minor tonality or offering a distinctive Ab Major voicing. It's perfectly suited for compositions that benefit from a deep, resonant base and lush open harmonies, often found in atmospheric or reflective musical styles.

One of the most exciting aspects of this setup, as highlighted by its creator, is its immediate versatility. By simply placing a finger on the 1st fret of the 6th string, you instantly unlock an open Db Major 9th chord! The notes transform to Db Ab Eb Ab C Eb, revealing a bright, expansive, and highly sophisticated jazz-infused voicing. This showcases the creative depth and harmonic flexibility embedded within the tuning's design.

Technical Analysis:

The open notes for this tuning are: C2 G#3 D#4 G#4 C4 D#5. Analysing the constituent notes (C, G#, D#, G#, C, D#), we identify the core elements as C, Ab (G#), and Eb (D#). This forms an Ab Major triad (Ab, C, Eb) layered over a low C, which is commonly notated as Ab/C. The tuning features a strong presence of octave and unison notes (C on 6th and 2nd strings, Ab on 5th and 3rd strings, Eb on 4th and 1st strings), contributing to its full and sustained open chord sound. The intervallic structure, particularly from the lowest C, suggests a versatile harmonic palette suitable for both minor and major contexts, making it a compelling choice for exploration beyond standard chord shapes.

How to Tune Your Guitar:

To achieve the "Open Ab Major / C" tuning from standard EADGBe, carefully adjust each string as follows:

• 6th String (Low E): Tune down 4 semitones to C2. (Note: Tuning down 4 semitones is a significant adjustment. While within acceptable limits, consider a heavier gauge string if you frequently use this tuning or experience excessive slack.)
• 5th String (A): Tune down 1 semitone to G#3 (Ab3).
• 4th String (D): Tune up 1 semitone to D#4 (Eb4).
• 3rd String (G): Tune up 1 semitone to G#4 (Ab4).
• 2nd String (B): Tune up 1 semitone to C4.
• 1st String (High E): Tune down 1 semitone to D#5 (Eb5).

Always tune carefully and use a reliable tuner. Pay attention to your guitar's neck relief when making significant tuning changes.