Tuning Analysis: Apex Drop A0

This is an extremely low and uniquely structured 9-string guitar tuning, originally known as Emmure A0. As described, it's a signature sound used by Josh Travis in many Emmure tracks, stemming from an alteration of the tuning used by Glass Cloud on their 'Perfect War Forever' EP. This heritage immediately suggests its suitability for heavy, progressive, and often dissonant extreme metal genres like djent and deathcore.

Technical Breakdown

This 9-string tuning establishes an incredibly deep sonic foundation with its lowest note, A0, which is well below the standard low tunings found on most extended-range guitars. The full sequence of notes from lowest to highest is A0, D1, A1, D2, C3, C3, G3, A3, D5#.

• The Low End (Strings 9-6): A0-D1-A1-D2
  This section forms a powerful, resonant foundation. The intervals across these four strings are a perfect fourth (A0-D1), followed by a perfect fifth (D1-A1), and then another perfect fourth (A1-D2). This 'A-D-A-D' pattern allows for exceptionally thick open-string power chords. Strumming these strings open yields a rich, deep sound, heavily influenced by A with a strong D presence.
• The Mid-Range (Strings 5-4): C3-C3
  A highly unconventional and distinctive feature of this tuning is the unison C3 on both the 5th and 4th strings. This creates a powerful drone or rhythmic element when struck together. While it makes standard chord shapes across these specific strings challenging, it opens up unique sonic textures for sustained notes, percussive chugs, or creating octave effects when coupled with other notes.
• The High End (Strings 3-1): G3-A3-D5#
  The upper strings present a more varied set of intervals. From the 4th string C3 to the 3rd string G3 is a perfect fourth. Then, from G3 to A3 is a whole step. Finally, the top string, D5#, is quite high, creating a very bright and piercing element. The interval from A3 to D5# is a compound augmented fourth, or a D# an octave above the A. This highest D5# allows for searing lead lines, dissonant melodies, and bright, cutting textures that stand out against the extremely low foundation.

Open Chords and Voicings

Given the A0-D1-A1-D2 pattern in the lowest strings, open power chords are readily available. Simply strumming strings 9, 8, 7, and 6 together yields a rich A/D suspended sound or can be seen as an A5 with a prominent D. By holding down a single fret across these strings, you can easily access heavy, thick power chords for massive rhythmic impact. The unison C3s on strings 5 and 4 can be leveraged for percussive muted riffs or open drones, creating a unique texture. Standard open chords will be largely redefined and require creative fingerings due to the unique intervals and the C3-C3 unison. This tuning excels at creating deep, aggressive sonic landscapes rather than conventional harmonic structures.

How to Tune Your Guitar

Achieving this tuning requires significant adjustments from standard tunings. Please note the following movements for each string:

• 9th String: Starting from its previous state, tune down 4 semitones to reach A0. Due to the significant downward movement of 4 semitones, a heavier gauge string is strongly advised to maintain optimal tension and tone.
• 8th String: Starting from its previous state, tune down 4 semitones to reach D1. Similar to the 9th string, a heavier gauge string is recommended for this 4-semitone drop.
• 7th String: Starting from its previous state, tune down 2 semitones to reach A1.
• 6th String: Starting from its previous state, tune down 2 semitones to reach D2.
• 5th String: Starting from its previous state, tune up 3 semitones to reach C3.
• 4th String: Starting from its previous state, tune down 2 semitones to reach C3.
• 3rd String: Keep as is; no change (0 semitones) to remain at G3.
• 2nd String: Starting from its previous state, tune down 2 semitones to reach A3.
• 1st String: Starting from its previous state, tune down 1 semitones to reach D5#.

Important String Gauge Note: For strings requiring a change of 4 or more semitones (either up or down), a different string gauge is generally advised to ensure proper string tension, intonation, and to prevent string breakage or damage to your guitar.