The "Duk Koo Kim" tuning, named after the Sun Kil Moon song, offers a distinctive and moody sonic landscape. While the initial verbal description provided was "C G C D A D", the actual technical tuning, as detailed by the notes, is C# G# C# D# A# D#.

Verbal Analysis

This tuning departs significantly from standard EADGBe, creating a sound that is both rich and somewhat open, yet with a unique underlying tension. The lower three strings (C# G# C#) provide a powerful, resonant C# power chord foundation. This deep, solid base is then contrasted by the higher strings (D# A# D#), which form a D# power chord, a major second above the root C#. The interplay between C# and D# across the open strings creates a suspended, almost ethereal quality, lending itself well to atmospheric compositions, intricate fingerstyle, and melodic lines that can dance over a sustained harmonic drone. It's particularly effective for evoking a melancholic or contemplative mood, characteristic of Sun Kil Moon's sound.

Technical Analysis

The open strings are tuned to C#3 G#3 C#4 D#4 A#4 D#5 (from low to high E). Let's examine the intervals from the lowest C#:

• String 6 (C#3) to String 5 (G#3): Perfect Fifth (P5)
• String 5 (G#3) to String 4 (C#4): Perfect Fourth (P4) – an octave C#
• String 4 (C#4) to String 3 (D#4): Major Second (M2)
• String 3 (D#4) to String 2 (A#4): Perfect Fifth (P5)
• String 2 (A#4) to String 1 (D#5): Perfect Fourth (P4) – an octave D#

The open strings collectively form a C#sus2(add6) chord (C#, D#, G#, A#). The repetition of C# and D# notes across octaves adds fullness and resonance. This is not a conventional open major or minor tuning, but rather a sophisticated, suspended voicing designed to offer specific harmonic possibilities. The consistent Perfect Fourth/Fifth relationships between adjacent strings (except for String 4 to 3) make it easy to barre chords and move shapes up and down the neck, while the Major Second interval provides a characteristic tension.

Open String Harmony & Playability

The open strings themselves resonate as a unique C#sus2(add6) chord, allowing for immediate, rich harmonic textures with simple strumming. The strong power chord formations on the lower (C#5 from C#3-G#3) and upper (D#5 from D#4-A#4) string sets make it straightforward to create powerful, droning rhythms. Barring all strings at any given fret will yield a movable version of this C#sus2(add6) chord, transposed to the new root. This encourages experimentation with melodic lines that incorporate the open string drones, creating a spacious and often melancholic sound.

How to Tune Your Guitar

To achieve the "Duk Koo Kim" tuning from standard EADGBe, follow these string movements carefully:

• String 6 (Low E): Tune down 3 semitones to reach a C#3.
• String 5 (A): Tune down 1 semitone to reach a G#3.
• String 4 (D): Tune down 1 semitone to reach a C#4.
• String 3 (G): Tune down 4 semitones to reach a D#4.
• String 2 (B): Tune down 1 semitone to reach an A#4.
• String 1 (High e): Tune down 1 semitone to reach a D#5.

Important Note on String Tension: Tuning strings significantly up or down can affect string tension and potentially damage your guitar. While most of these adjustments are moderate, tuning String 3 down 4 semitones is at the upper end of recommended changes for a standard gauge string. For optimal playability and to avoid potential issues, especially if you plan to keep your guitar in this tuning for extended periods, consider using a lighter gauge string for String 3 or a heavier gauge set overall to accommodate the lower tension of the other strings.

String 6: Tuned to C#3 (Low C#)

String 5: Tuned to G#3

String 4: Tuned to C#4

String 3: Tuned to D#4

String 2: Tuned to A#4

String 1: Tuned to D#5 (High D#)