The "Apocalyptic A Seven" tuning is a formidable 7-string guitar setup, originally conceived for playing the intricate and heavy compositions of Humanity's Last Breath. It is a highly modified variant of Drop A, designed to deliver extreme low-end aggression combined with unique upper-register tension.

This tuning transforms the standard 7-string into a sonic beast, starting with a guttural A1 on the lowest string, followed by E2, A2, D3, G3, C#5, and culminating in D4 on the highest string. This configuration creates a vast tonal palette, perfect for modern deathcore, djent, and progressive metal where crushing riffs and dissonant textures are paramount.

Technical Analysis:

• Root Note: The tuning is centered around a low 'A', providing a deep and resonant foundation.
• Open String Intervals (Low to High):
  • String 7 (A1) to String 6 (E2): Perfect 5th
  • String 6 (E2) to String 5 (A2): Perfect 4th
  • String 5 (A2) to String 4 (D3): Perfect 4th
  • String 4 (D3) to String 3 (G3): Perfect 4th
  • String 3 (G3) to String 2 (C#5): Augmented 4th (Tritone)
  • String 2 (C#5) to String 1 (D4): Minor 2nd
• The prevalence of Perfect 4ths between the E2, A2, D3, and G3 strings, combined with the initial Perfect 5th from A1 to E2, facilitates easy power chord shapes and chugging riffs across the lower and middle registers.
• The highly dissonant Augmented 4th (tritone) between G3 and C#5, followed by a Minor 2nd between C#5 and D4, introduces significant tension and complexity in the upper register. This is a hallmark of modern heavy music, allowing for unique harmonic clusters and jarring lead lines.

Open String & Chordal Opportunities:

• A5 Power Chord: The lowest three strings (A1-E2-A2) are perfectly tuned to form a massive open A5 power chord, ideal for bone-crushing open string riffs and rhythmic foundations.
• A sus4: Including the 4th string (D3) with the lowest three creates an open A sus4 chord (A-E-A-D), offering a more open, yet still heavy, sound.
• Dissonant Open Harmony: The full open tuning (A E A D G C# D) is not a traditional chord but a complex, dissonant voicing. It features elements of A major (C#), A minor (G), and A sus4 (D), creating a rich, tension-filled soundscape perfect for experimental ambient passages or jarring chordal impacts.
• Power Chord Shapes: Standard 3-finger power chord shapes are easily accessible across the P4 intervals on strings 6-5-4-3. The low A-E-A also makes low power chords effortless.
• Unique Voicings: The G-C#-D cluster on strings 3-2-1 allows for highly distinctive arpeggios and voicings that would be difficult to achieve in standard tunings, facilitating creative melodic and harmonic exploration in the higher register.

Tuning Notes:

String 7 (Lowest): A1
String 6: E2
String 5: A2
String 4: D3
String 3: G3
String 2: C#5
String 1 (Highest): D4

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

To achieve the "Apocalyptic A Seven" tuning, follow these precise adjustments from a standard 7-string tuning (B E A D G B E):

• String 7 (Lowest B): Tune down 2 semitones to A1.
• String 6 (E): Keep as is; no change (0 semitones). The target note is E2.
• String 5 (A): Keep as is; no change (0 semitones). The target note is A2.
• String 4 (D): Keep as is; no change (0 semitones). The target note is D3.
• String 3 (G): Keep as is; no change (0 semitones). The target note is G3.
• String 2 (B): Tune up 2 semitones to C#5. (Note: Tuning up 2 semitones is generally safe, but always tune slowly and cautiously.)
• String 1 (Highest E): Tune down 2 semitones to D4.

String Gauge Advisory: For significant tuning changes (typically exceeding 4 semitones up or down), a different string gauge may be advised to maintain optimal tension and prevent string breakage or damage to the instrument. In this tuning, most strings have minor adjustments, with the maximum change being 2 semitones, which is generally within safe limits for standard string gauges. However, always exercise caution when altering string tension.