Opals (from anc.Gr. “opallios”, meaning “to see a change of color”) are precious stones whose colour changes with the point/angle of observation, unveiling iridescent rainbow shades; they may be transparent, translucent, or opaque, and the background color may be white, black, or nearly any color of the visual spectrum. 

Some of these qualities, together with more general phenomena such as interference and diffraction (of light, of sound), have been important concepts / guidelines in the creation of this piece.

The guitar’s quarter-tone fretboard opens up to non-tempered possibilities (both melodic and harmonic), and the hexaphonic system allows the separation, the individual manipulation and spatialization of its six strings, “splitted and reassembled” by the live electronics into a new, diffused instrument.