The 'Drop A 7-String' tuning is a powerful and popular modification of the standard 7-string guitar tuning. It takes the lowest string of a standard 7-string setup (which is typically B1) and drops it down a whole step (two semitones) to A1. The remaining six strings retain their standard tuning of E-A-D-G-B-E (from lowest to highest of these six).

Technically, the open string notes for this tuning are A1-E2-A2-D3-G3-B3-E4. This configuration creates an incredibly heavy and resonant low 'A' fundamental, making it a go-to tuning for genres like progressive metal, death metal, djent, and other heavy music styles where deep, detuned riffs are paramount. The dropped A string allows for easy one-finger power chords across the lowest strings (A-E-A), providing immense sonic weight and facilitating complex, low-end riffing that would be more challenging in standard tuning.

The familiar E-A-D-G-B-E intervals on the upper six strings mean that most scales, chords, and arpeggios learned in standard tuning are directly transferable, while the dropped A string offers new melodic and rhythmic possibilities on the lowest register. This blend of familiarity and extended range makes 'Drop A 7-String' a versatile and expressive tuning for players looking to explore the darker, heavier side of the guitar's sonic spectrum.

Open String Notes:

• String 7 (lowest): A1
• String 6: E2
• String 5: A2
• String 4: D3
• String 3: G3
• String 2: B3
• String 1 (highest): E4

How to Tune from Standard 7-String (B-E-A-D-G-B-E):

• String 7 (lowest): Tune down 2 semitones from B1 to A1.
• String 6: Keep as is; no change (0 semitones) at E2.
• String 5: Keep as is; no change (0 semitones) at A2.
• String 4: Keep as is; no change (0 semitones) at D3.
• String 3: Keep as is; no change (0 semitones) at G3.
• String 2: Keep as is; no change (0 semitones) at B3.
• String 1 (highest): Keep as is; no change (0 semitones) at E4.

Note on String Gauge: The tuning adjustment for String 7 involves tuning down 2 semitones. This is a moderate change and is generally safe for standard string gauges. However, some players might prefer a slightly thicker gauge for String 7 to maintain optimal tension and tone when played at this lower pitch.