The "Eadd9 harmonic" tuning, as the original description suggests, is the result of some creative knob-twisting, designed for an acoustic or electric Guitar.

Verbal Analysis

This is a rich and resonant tuning, immediately presenting a vibrant Eadd9 chord when strummed open. The strong presence of the B note across multiple strings (B2 on both the 5th and 4th strings, and B3 on the 1st string) creates a unique, almost drone-like quality, reinforcing the fifth of the E chord. The closely voiced F#4 and G#4 on the 3rd and 2nd strings add a lovely harmonic density, suggesting a bright, major tonality with an open, suspended feel from the added 9th. It would be excellent for open, ringing arpeggios, fingerstyle compositions, or even powerful, sustained chords where you want that "wall of sound" effect, particularly in the key of E Major or its relative C# minor. The duplicate B2 on strings 5 and 4 is a highly unusual choice, promising a very thick, almost unison-like texture in the lower register, which could be exploited for unique rhythmic or harmonic effects.

Technical Analysis

The open strings are tuned to E2-B2-B2-F#4-G#4-B3. Breaking this down:

• The root note E (E2) is on the lowest string.
• The 5th, B, is prominently featured on three strings (B2, B2, B3), providing immense resonance and sustain for the dominant. The duplicated B2 on the 5th and 4th strings is a distinctive feature, creating a thick unison in the bass.
• The 9th (F#4) is on the 3rd string, sitting two semitones above the root's octave (E3) and adding a bright, open quality.
• The major 3rd (G#4) is on the 2nd string, completing the major triad.
• The highest string (B3) is another 5th, an octave below the G#4, creating an interesting voice leading and contributing to the overall ringing quality.

How to Tune

To achieve the "Eadd9 harmonic" tuning from standard E-A-D-G-B-e (from low to high):

• 6th String (Low E): Keep as is; no change (0 semitones).
• 5th String (A): Tune up 2 semitones to B2. Exercise caution when tuning up.
• 4th String (D): Tune down 3 semitones to B2.
• 3rd String (G): Tune down 1 semitone to F#4.
• 2nd String (B): Tune down 3 semitones to G#4.
• 1st String (High E): Tune down 5 semitones to B3. Note: Tuning down 5 semitones is a significant change; a lighter gauge string might be advisable for optimal tension and playability.

Remember to tune carefully and check intonation after making significant changes to string tension.

String 6: E2 (Lowest string, two octaves below middle C)
String 5: B2 (An octave below middle C)
String 4: B2 (An octave below middle C, same pitch as String 5)
String 3: F#4 (Above middle C)
String 2: G#4 (Above middle C)
String 1: B3 (Just below middle C)