The Double Drop D 7th tuning is a fascinating alteration of standard guitar tuning (E-A-D-G-B-E). As its name suggests, it builds upon the familiar Double Drop D (D-A-D-G-B-D) by introducing a distinctive modification: the second string is raised a semitone from B to C. This subtle change dramatically transforms the harmonic landscape. This tuning could also be seen as a variation on Gsus4 tuning with the fifth string remaining on A.

Verbally, this tuning delivers a rich, open sound that leans towards a dominant suspended quality. The two outer D strings (low and high) provide a strong, resonant fundamental, characteristic of drop tunings, making it excellent for heavy riffs and expansive textures. The A-D-G within the middle strings offers familiar melodic and chordal possibilities, but the C on the second string adds a distinctive tension and color.

Technically, the open strings are tuned to D2-A2-D3-G3-C4-D4. When played open, these notes form a D7sus4 chord (D-G-A-C) with the root (D) and fifth (A) reinforced across multiple octaves. The C natural on the second string functions as the minor seventh, while the G on the third string creates the suspended fourth. This complex yet powerful voicing is neither major nor minor, offering a versatile palette for blues, rock, fusion, and even contemporary folk music.

The structure makes power chords incredibly accessible, particularly those rooted on D, as the 6th, 5th, and 4th strings form D-A-D. Simply barring across these lower strings will yield powerful D chords. Similarly, chords rooted on the 5th string (A) can also be easily constructed. The unique relationship between the G, C, and high D strings allows for interesting melodic lines and voicings that would be challenging in standard tuning. Exploring shapes that utilize the open D, G, and C strings will unlock a wide array of suspended and dominant 7th voicings, providing a modern and expressive tonal quality.

Tuning Notes:

• String 6 (Low E string): D2
• String 5 (A string): A2
• String 4 (D string): D3
• String 3 (G string): G3
• String 2 (B string): C4
• String 1 (High E string): D4

How to Tune:

To achieve the Double Drop D 7th tuning, start from standard EADGBe tuning and make the following adjustments:

• String 6 (Low E): Tune down 2 semitones from E to D.
• String 5 (A): Keep as is; no change (A).
• String 4 (D): Keep as is; no change (D).
• String 3 (G): Keep as is; no change (G).
• String 2 (B): Tune up 1 semitone from B to C.
• String 1 (High E): Tune down 2 semitones from E to D.

Important Note on String Tension: Generally, tuning up or down more than 4 semitones can put significant stress on your strings and instrument neck, and a different gauge string may be advisable. For this tuning, all string adjustments are within a safe range for standard gauge strings, but always tune carefully and gradually, especially when increasing string tension. Ensure your instrument is properly set up for alternative tunings.