Tuning Overview: A Min 9

The A Min 9 tuning transforms your guitar into a rich, resonant soundscape, optimized for an A minor 9th tonality. As described, it's a deep dive into an altered tuning, branching off from a DAEFCE base to create a complex harmonic foundation. This tuning is not for the faint of heart, as it involves significant string tension changes, but the resulting sound is incredibly rewarding for jazz, fusion, or ambient styles.
With notes A1-E2-B2-C3-G3-B3 from thickest to thinnest, this tuning spreads out the intervals, creating a wide, open sound. The core A minor 9th (A-C-E-G-B) is implied within the open strings, making it easy to evoke sophisticated jazz voicings with minimal effort. You'll find that open position chords take on new colors, often sounding like rich extensions or suspensions.
Specifically, the open strings A-E-B-C-G-B contain the notes A (root), C (minor 3rd), E (perfect 5th), G (minor 7th), and B (major 9th). This means playing all open strings together creates an A minor 9th chord without fretting a single note, offering immediate harmonic depth. The two B notes an octave apart (B2, B3) add sparkle and sustain.
Due to the wide intervals and the clustering of minor 9th components, this tuning will lend itself well to fingerstyle playing, arpeggios, and drones. Sliding into chords or using partial voicings will reveal beautiful, unexpected harmonies. Chords like Am9, Am11, and even Cmaj7#11 (relative to C) or G6/9 (relative to G) could easily be voiced with just one or two fretted notes, taking advantage of the open string resonance.

Technical Analysis: Interval Structure

• String 6 (A1) to String 5 (E2): Perfect 5th (7 semitones)
• String 5 (E2) to String 4 (B2): Perfect 5th (7 semitones)
• String 4 (B2) to String 3 (C3): Minor 2nd (1 semitone)
• String 3 (C3) to String 2 (G3): Perfect 5th (7 semitones)
• String 2 (G3) to String 1 (B3): Major 3rd (4 semitones)

This unusual interval structure (P5-P5-m2-P5-M3) offers unique fingering possibilities and chord voicings not easily achieved in standard tuning. The consecutive perfect fifths on the lower strings provide a deep, resonant bass, while the minor second between strings 4 and 3 creates tension and color, allowing for close harmonies. The final major third provides a bright upper register contrast.

How to Tune Your Guitar to A Min 9

This tuning requires significant adjustments from standard EADGBe. Please proceed with caution, especially when lowering string tension substantially. It's crucial to use a reliable tuner and tune gradually to avoid string breakage or neck stress.

• String 6 (Low E to A1): Tune down 7 semitones. Caution: This is a significant drop of 7 semitones. A heavier gauge string set is highly recommended for sustained use in this tuning to maintain proper tension.
• String 5 (A to E2): Tune down 5 semitones. Caution: This is a significant drop of 5 semitones. Consider a heavier gauge string for optimal performance.
• String 4 (D to B2): Tune down 3 semitones.
• String 3 (G to C3): Tune down 7 semitones. Caution: This is a significant drop of 7 semitones. A heavier gauge string set is highly recommended for sustained use in this tuning to maintain proper tension.
• String 2 (B to G3): Tune down 4 semitones. Caution: While not exceeding the threshold of 4 semitones, tuning down 4 semitones is a substantial change. Monitor string tension and intonation carefully.
• String 1 (High E to B3): Tune down 5 semitones. Caution: This is a significant drop of 5 semitones. Consider a heavier gauge string for optimal performance.

If you frequently use tunings with drops of 5 semitones or more, a dedicated set of strings with a heavier gauge (especially for the lower strings) will greatly improve the guitar's playability, intonation, and overall sound quality, reducing the risk of fret buzz and neck instability.

String 6 (Low E): Tuned to A1.
String 5 (A): Tuned to E2.
String 4 (D): Tuned to B2.
String 3 (G): Tuned to C3.
String 2 (B): Tuned to G3.
String 1 (High E): Tuned to B3.