The earliest version of Quicksilver and Refractive Light (QS/RL) was made for Barbara Held in 1994 as a piece that she could run on her own music system. It consisted of software for a Macintosh laptop computer linked to a single Proteus synthesizer, a pitch sensor and a microphone. It was intended to be performable with a flute or alto flute either in private or at concerts.

Since then a more luxurious version of the piece has developed, with three synthesizers instead of one and an input for a second musician. It has been "test driven" by several additional fine artists, among them Takehisa Kosugi, Steve Lacy, Maggi Payne and Jon Gibson. Other instruments besides flutes have turned out to be interesting to use in its performances.
In QS/RL the software is indifferent to which particular pitches are being played, responding instead to changes in the loudness of sustaining sounds within low and high register regions that can be flexibly set during performance.That makes for a situation more relaxed than in other of my software-based pieces where "hits" on particular pitches are required to elicit reactions. Each of the two parts of QS/RL has eight subsections that can be entered in any order and engaged for any duration. A number of alterable options, displayed on the laptop's screen, govern details of the sound textures and ongoing interaction. The recording with Maggi Payne was made at the Center for Contemporary Music at Mills College in November 1995, in the same studio where we had recorded together in the seventies. Penlight is a sound installation version of the piece made for STUDIO FIVE, Beekman, New York, which uses the same music software, but a different input situation.