This unique guitar tuning, named "open a add4 capo 4", refers to a specific setup that, when a capo is placed at the 4th fret, causes the open strings to sound as F#3, C#4, G#4, C#5, F4, G#5 from low to high. The provided description "its daeac#e tuning capo 4" correctly identifies the base, un-capoed tuning.

Technical Analysis:

• The fundamental tuning of the guitar's open strings, without the capo, is D3 A3 E4 A4 C4 E5 (D A E A C E). This base tuning can be characterized as a Dsus2-like chord (D-E-A) with an added minor seventh (C). This gives it a complex, slightly bluesy or modal feel, similar to a Dm7(add9 no3) voicing.
• When the capo is applied at the 4th fret, all notes are raised by four semitones. The resulting sounding open notes of F#3, C#4, G#4, C#5, F4, G#5 effectively create an F#7sus2 chord when strummed open. The unique notes in this chord are F# (root), G# (major 2nd/9th), C# (perfect 5th), and F (minor 7th). The tuning also features octave doublings of C# and G# for a rich, full sound.
• The prominent minor 7th (F) and major 2nd (G#) relative to the F# root provide a distinctive harmonic texture, allowing for both sweet suspensions and blues-inflected voicings. The intervals and note repetitions contribute to a highly resonant and sustained open sound.

Verbal Description & Playability:

This tuning offers a bright, full, and slightly melancholic sound due to its F#7sus2 open chord. It's excellent for creating atmospheric drone-based music, intricate fingerstyle arrangements, or for experimenting with unique open string voicings. The open strings themselves form a complex chord that resonates with depth. Sliding into chords or using partial barres can yield rich harmonies that stand out from standard tuning. The close proximity of F and F# (a minor 2nd interval that becomes a major 7th across an octave, or a bluesy half-step) on adjacent strings provides a natural avenue for expressive bends or slides.

Suggested Open Chords & Shapes:

• Open Strum: An immediate F#7sus2 chord, perfect for rhythmic accompaniment or starting a piece.
• Barre Chords: A full barre across any fret will produce a 7sus2 chord of the corresponding root (e.g., barre at 2nd fret for G#7sus2, barre at 7th fret for C#7sus2).
• Drone Playing: The repeated C# and G# notes across the middle strings are perfectly positioned for maintaining a sustained drone while melody lines are played on the higher or lower strings.
• Blues & Modal: The F on the 2nd string against the F# root offers natural opportunities for bluesy slides, subtle dissonances, and exploring modal harmonies.

How to Tune to 'open a add4 capo 4' (Notes Before Capo)

This tuning involves significant upward adjustments for most strings from standard EADGBe tuning. It is strongly recommended to use a lighter gauge string set or exercise extreme caution, especially for strings tuned up 4 or more semitones, as this increases string tension considerably and may risk string breakage or damage to your instrument.

• String 6 (Low E): From standard E3, tune up 2 semitones to F#3.
• String 5 (A): From standard A3, tune up 4 semitones to C#4. ⚠️ Caution: Significant tension increase.
• String 4 (D): From standard D4, tune up 6 semitones to G#4. ⚠️ Extreme Caution: Very high tension increase. A lighter gauge string is advised.
• String 3 (G): From standard G4, tune up 6 semitones to C#5. ⚠️ Extreme Caution: Very high tension increase. A lighter gauge string is advised.
• String 2 (B): From standard B4, tune up 6 semitones to F4. ⚠️ Extreme Caution: Very high tension increase. A lighter gauge string is advised.
• String 1 (High E): From standard E5, tune up 4 semitones to G#5. ⚠️ Caution: Significant tension increase.

Once tuned to D3 A3 E4 A4 C4 E5 (the notes derived from the movements above), place a capo at the 4th fret. The open strings will then sound as F#3, C#4, G#4, C#5, F4, G#5 respectively.