Verbal Analysis:

"Charlie's Sharpened D" offers a unique and resonant sound, as suggested by its original description of "just messing about" on a classical guitar. This tuning descends significantly from standard, giving the instrument a deep, almost brooding character on the lower strings, while the higher strings introduce a distinctly bluesy or jazzy flavour with their sharpened (or flattened) notes. The overall feel is rich, dark, and full, suggesting a soundscape suitable for atmospheric pieces, blues, jazz-fusion, or even a modern classical approach.

The significant drops on the low E and A strings (4 semitones each) will result in a much slacker feel, which can be great for expressive bends and a warm, bassy attack. However, it also demands a delicate touch to avoid intonation issues and fret buzz. The close intervals on the lower strings create a drone-like quality, while the higher string alterations open up new harmonic possibilities that stray far from conventional major-key tunings.

Technical Analysis:

This tuning transforms the guitar into: C2-F2-C3-F3-A#4-D#5 (or enharmonically C2-F2-C3-F3-Bb4-Eb5).

• The lowest four strings (C-F-C-F) establish a strong foundational harmony, essentially a Csus4 chord or an Fsus2 chord, with a recurring perfect fourth interval (C to F). This creates a powerful, resonant drone effect that can underpin various melodic ideas.
• Introducing A#4 (Bb4) on the second string and D#5 (Eb5) on the first string adds a distinct minor and bluesy character. The combined open strings spell out the unique note collection of C, F, Bb, Eb.
• This open voicing forms a C minor 7 (add11) chord (C-Eb-F-Bb) or an F7sus4 chord (F-Bb-C-Eb) if F is considered the root. This is a sophisticated harmonic cluster that lends itself to a modern jazz or blues idiom, offering immediate access to rich, complex harmonies without extensive fretting.

Chords & Playability:

• Open Chord Voicings: The open strings themselves form a beautiful and complex chord, a Cm7(add11) or F7sus4, making it instantly playable for atmospheric textures.
• Power Chords: Due to the C-F-C-F pattern on the lower strings, two-finger power chords (root-5th) will be readily available and resonate powerfully. For example, simply fretting the 6th and 4th strings at the same fret will yield a perfect 5th interval.
• Barre Chords: A single-finger barre across the lower four strings will create variations of a Csus4 or Fsus2 chord, easily shifted up and down the neck. Barre chords involving all strings will produce complex, dense voicings reflecting the open tuning's inherent harmony.
• Melodic & Improvised Play: The minor 7th and 11th intervals provided by the open strings make this tuning excellent for exploring blues, jazz, and even modal improvisations, particularly in the keys of C minor, F minor, or F dominant.

Open Tuning Notes:

String 6 (Low E): C2
String 5 (A): F2
String 4 (D): C3
String 3 (G): F3
String 2 (B): A#4
String 1 (High E): D#5

How to Tune "Charlie's Sharpened D":

To achieve "Charlie's Sharpened D" from standard E-A-D-G-B-e tuning, follow these precise adjustments:

• String 6 (Low E): Tune down 4 semitones to C2. (Note: Tuning down 4 semitones significantly reduces string tension. For optimal playability and tone, especially if you plan to keep your guitar in this tuning, consider using a heavier gauge string for the low E.)
• String 5 (A): Tune down 4 semitones to F2. (Note: Similar to String 6, a heavier gauge string may be beneficial for sustained use in this lower tuning.)
• String 4 (D): Tune down 2 semitones to C3.
• String 3 (G): Tune down 2 semitones to F3.
• String 2 (B): Tune down 1 semitone to A#4.
• String 1 (High E): Tune down 1 semitone to D#5.

Always tune carefully, especially when making large adjustments, to avoid string breakage or damage to your instrument. Use a reliable tuner to ensure accuracy.