Tuning Analysis: Iris (D1 A1 D2 G2 B2 E3)

The 'Iris' tuning, as defined by its open strings D1 A1 D2 G2 B2 E3, presents a profoundly low and resonant setup for the guitar. This tuning aligns with the provided description of being suitable for the song 'Iris' and 'other things,' suggesting a unique sonic palette well beyond standard applications. It's essentially a standard EADGBe tuning transposed down a full octave for most strings, with the lowest string (originally E) then further dropped by a whole step to D in that lower octave (D1). This creates an extremely deep, thick, and powerful soundscape, ideal for heavy, droning passages, atmospheric sound design, or experimental music where a rich, low-end presence is paramount.

Technical Observations:

• Open Notes: D1, A1, D2, G2, B2, E3 (from low to high).
• Intervals from lowest string (D1): The tuning establishes a strong D-centric tonality. From the low D1, the intervals are: Perfect 5th (A1), Perfect Octave (D2), Perfect 11th (G2, equivalent to a Perfect 4th above the D2 octave), Major 13th (B2, equivalent to a Major 6th above D2), and Major 16th (E3, equivalent to a Major 9th above D2).
• Chord Voicings:
  • The lowest three strings (D1-A1-D2) naturally form a powerful D5 (D power chord), providing an incredibly thick root and fifth foundation. This makes heavy, driving riffs particularly impactful.
  • Playing all open strings simultaneously yields a resonant Dsus2/add11 chord (D-A-D-G-B-E), creating a full, open, and slightly ambiguous harmonic texture that can be rich for droning or ambient compositions.
  • Traditional major and minor chord shapes on the upper strings will remain familiar but will be transposed down an entire octave. For example, an open G major chord shape (G-B-E on strings 3, 2, 1) will produce G2-B2-E3, a very deep and rich G major triad.
  • Barring across any frets on the lower strings will easily create powerful, low-frequency chords, enhancing its suitability for genres requiring a heavy bottom end.
• String Gauge Recommendation: Due to the extreme down-tuning by a full octave (and more for the lowest string), significantly heavier gauge strings are not just advisable but essential. This will help maintain playable tension, ensure proper intonation, and prevent strings from feeling overly floppy or producing excessive buzzing. Standard gauge strings will be far too loose for this tuning's intended depth.

How to Tune (from Standard EADGBe)

To achieve the 'Iris' tuning based on the provided string movement data, please adjust your guitar from standard EADGBe tuning as follows. It's important to note that significant down-tuning is involved for most strings. For movements exceeding 4 semitones (up or down), a different string gauge may be advisable for optimal playability, tension, and tone.

• 6th String (Low E): Tune down 4 semitones. The original note E will become C#. (Movement: -4 semitones; a different gauge string is advised.)
• 5th String (A): Tune down 2 semitones. The original note A will become G.
• 4th String (D): Tune down 2 semitones. The original note D will become C.
• 3rd String (G): Tune down 2 semitones. The original note G will become F.
• 2nd String (B): Tune down 3 semitones. The original note B will become G#. (Movement: -3 semitones; a different gauge string is advised.)
• 1st String (High E): Tune down 3 semitones. The original note E will become C#. (Movement: -3 semitones; a different gauge string is advised.)