The 'Iris' tuning, famously used by The Goo Goo Dolls, presents a truly unique and resonant soundscape on the guitar. Characterized by its incredibly low bass string and the striking drone of five D notes across the upper strings, this tuning creates a deep, melancholic, and expansive atmosphere. It's a tuning designed to evoke a specific emotional response, often utilized for its ringing, open qualities that lend themselves well to strumming and arpeggiated patterns. The sheer density of the D notes provides a powerful, sustained drone, allowing for simple fretboard movements to create rich harmonic textures.

This is an unconventional drone tuning for a 6-string Guitar. The open notes from low to high are B1-D2-D3-D3-D4-D4. This configuration strongly implies a B minor tonality due to the B root and the dominant D notes (which act as a minor third over B). When strummed open, this tuning forms a rich B minor chord (specifically, a B minor with a sustained D drone, or a Dadd6/B). The repetition of D across five strings means that open string strumming will produce a powerful, resonant sound. Chord shapes will be heavily influenced by this drone; for example, barring across all D strings with the B string fretted at the 2nd fret (C#) would create a C# minor sound, but the heavy D drone might lean it towards a more ambiguous, suspended quality. The significant detuning on multiple strings, especially the lower ones, necessitates careful string gauge selection to maintain tension and tone.

How to Tune:

• String 6 (Low E): Tune down 5 semitones (two and a half steps) from E to B.
  (Note: Tuning down 5 semitones is a significant change; a heavier gauge string like a .050 bass string is highly recommended.)
• String 5 (A): Tune down 7 semitones (three and a half steps) from A to D.
  (Note: Tuning down 7 semitones is a very significant change; a heavier gauge string like a .046 low E string is highly recommended.)
• String 4 (D): Keep as is; no change (0 semitones) from D to D.
• String 3 (G): Tune down 5 semitones (two and a half steps) from G to D.
  (Note: Tuning down 5 semitones is a significant change; a heavier gauge string like a .026 D string is highly recommended.)
• String 2 (B): Tune up 3 semitones (one and a half steps) from B to D.
  (Note: Tuning up 3 semitones is a moderate change; proceed with care. A .010 gauge high E string is mentioned, which should handle this tension.)
• String 1 (High E): Tune down 2 semitones (one whole step) from E to D.

B1
D2
D3
D3
D4
D4