This tuning, famously used by Coldplay for their song "Til Kingdom Come," creates a profoundly resonant and expansive sound. It's a C-centric open tuning that delivers a full, almost piano-like harmonic landscape when played open.

Verbally, the significant downtuning of the low E and high e strings by four semitones each creates a wonderfully loose and expressive feel, conducive to fluid bends and a distinct warmth in tone. The open strings (C-A-C-G-B-C) naturally form a lush C major 7 chord with an added 6th (A). This makes it exceptionally easy to construct vast, open harmonies and shimmering arpeggios, particularly in the key of C major. The arrangement encourages melodic playing across the strings while maintaining a strong, consonant harmonic foundation. Simple barres or single-finger fretting can unlock complex-sounding voicings due to the unique intervallic structure.

Technically, this tuning is C2-A2-C3-G3-B3-C4. Compared to standard EADGBe, the 6th string (low E) and 1st string (high e) are substantially lowered by 4 semitones to C, while the 4th string (D) is dropped by 2 semitones to C. The 5th (A), 3rd (G), and 2nd (B) strings remain at their standard pitches. The open strings reveal a Cmaj7add6 chord voicing. The intervallic relationships between adjacent strings are: a Perfect 6th (C-A), a minor 3rd (A-C), a Perfect 5th (C-G), a Major 3rd (G-B), and a minor 2nd (B-C). This unique intervallic structure facilitates wide voicings and a rich harmonic spectrum centered around C. The substantial downtuning on the outer strings results in slacker string tension, which is often desirable for the specific feel of this song. However, for those preferring a tighter string feel, heavier gauge strings might be advised for the 6th and 1st strings.

The target notes for this tuning are:

• String 6 (low E): C2
• String 5 (A): A2
• String 4 (D): C3
• String 3 (G): G3
• String 2 (B): B3
• String 1 (high e): C4

How to Tune:

To achieve the 'Coldplay' tuning from standard EADGBe, follow these steps:

• String 6 (Low E): Tune down 4 semitones from E to C2.
• String 5 (A): Keep as is; no change (0 semitones) from A to A2.
• String 4 (D): Tune down 2 semitones from D to C3.
• String 3 (G): Keep as is; no change (0 semitones) from G to G3.
• String 2 (B): Keep as is; no change (0 semitones) from B to B3.
• String 1 (High e): Tune down 4 semitones from E to C4.

Important Note on String Tension: Strings 6 and 1 are tuned down by 4 semitones. While this specific tension may be integral to the song's feel, tuning down 4 or more semitones can result in significantly looser string tension. If you prefer a tighter feel or are concerned about string floppiness, consider using a heavier gauge string set for these specific strings.