This unique tuning, which the original creator describes as suitable for "math rock type riffs," presents a fascinating and complex harmonic landscape. While the provided name "Cmaj7(#5, #9) Tuning" hints at its character, a closer look at the open string notes reveals a blend of familiar intervals and intriguing dissonances, creating a distinct and modern sound.

Verbal Analysis

At its core, this tuning is built around a strong C presence, featuring C notes on both the 6th (low E) and 4th (D) strings, along with a prominent G (perfect fifth) on the 3rd string. This creates a solid C power chord foundation across the lower strings. However, the tuning quickly veers into more experimental territory with the inclusion of G# (augmented fifth or minor sixth) on the 5th string, which introduces a striking tension or 'sharpness' to the C harmony. The higher strings, A# (minor seventh or flattened seventh) on the 2nd string and D (major ninth) on the 1st string, further enrich the texture, adding a bluesy or dominant flavour and an extended, open voicings. The simultaneous presence of both a perfect fifth (G) and an augmented fifth (G#) creates a rich, dissonant cluster that is characteristic of experimental or progressive genres.

Players can expect a deep, resonant low end with the C2, perfect for heavy riffs, while the higher strings offer bright, expansive tones. The overall sound is not overtly 'major' or 'minor' but rather ambiguous and highly adaptable, encouraging creative chord voicings and melodic lines. The open strings themselves form a complex chord (C-G#-C-G-A#-D) that could be interpreted as a C7(add9, #5) or C7(add9, b6), offering a rich, modern sound from the very first strum.

Technical Analysis

The open tuning is C2 - G3# - C3 - G3 - A4# - D4.

• String 6 (C2): The foundational root, providing a deep, resonant low end.
• String 5 (G3#): An augmented 5th (or minor 6th) above the root C, creating significant tension against the C and G notes. This G# (enharmonically Ab) adds a darker, more complex character.
• String 4 (C3): An octave above the low C, reinforcing the root.
• String 3 (G3): A perfect 5th above the root C, providing harmonic stability. Its presence alongside G# is key to the tuning's unique sound.
• String 2 (A4#): A minor 7th (enharmonically Bb) above the root C, contributing a dominant or bluesy character.
• String 1 (D4): A major 9th above the root C, adding an open, extended harmonic flavour.

The open string notes combine to form the unique set: C, G, G#, A#, D. This collection features a tonic (C), perfect fifth (G), augmented fifth/minor sixth (G#), minor seventh (A#/Bb), and major ninth (D). The simultaneous presence of G and G# is a defining characteristic, creating a unique sonic tension. Basic chords like C5 (power chord) are easily accessible across the lower strings. Shapes for minor 7th and dominant 7th chords may also present themselves due to the A# (Bb) on the 2nd string. The tuning promotes fingerings that highlight the extended harmonies and dissonances, making it ideal for experimental or progressive compositions where traditional chord shapes are less of a concern than textural and harmonic exploration.

String 6: The low E string is tuned down 4 semitones to C2. This provides a deep, foundational root for the tuning.

String 5: The A string is tuned down 1 semitone to G#3. This note introduces an augmented fifth or minor sixth to the open harmony.

String 4: The D string is tuned down 2 semitones to C3. This note reinforces the root an octave higher.

String 3: The G string remains as is at G3. This maintains the perfect fifth, crucial for the tuning's harmony.

String 2: The B string is tuned down 1 semitone to A#4. This adds a minor seventh (Bb) to the overall open chord.

String 1: The high E string is tuned down 2 semitones to D4. This adds a major ninth to the overall open chord.

How to Tune

To achieve this tuning, start from standard EADGBe tuning and adjust each string as follows:

• String 6 (Low E): Tune down 4 semitones to C2. This change of 4 semitones down is at the limit where considering a heavier gauge string is often recommended for optimal tension and tone.
• String 5 (A): Tune down 1 semitone to G#2. (Note: The `tuning_notes` for this tuning indicates G3#, an octave higher than the direct calculation from standard A2 down 1 semitone. Ensure your tuner correctly identifies the octave if aiming for G3#.)
• String 4 (D): Tune down 2 semitones to C3.
• String 3 (G): Keep as is; no change (0 semitones) at G3.
• String 2 (B): Tune down 1 semitone to A#3. (Note: The `tuning_notes` for this tuning indicates A4#, an octave higher than the direct calculation from standard B3 down 1 semitone. Ensure your tuner correctly identifies the octave if aiming for A4#.)
• String 1 (High E): Tune down 2 semitones to D4.

Important String Gauge Note: Tuning a string more than 4 semitones (up or down) from its standard pitch significantly alters string tension. For this tuning, specifically the 6th string which is adjusted by 4 semitones, it is at the threshold where using a different gauge string (typically heavier for downtuning) is often advised to maintain proper playability, intonation, and to prevent potential damage to your guitar or strings. For changes exceeding 4 semitones, a different string gauge is strongly recommended.