FireOrgan is a contemplative sanctuary of fire and sound, an extraordinary new instrument that uses fire, glass tubes, resonance, and thermodynamics to create an environment of deep, low tones activated by the presence of visitors and sometimes even fueled by their voices.

FireOrgan was created by Trimpin, an internationally known, Seattle-based German artist and composer, in conjunction with the Exploratorium exhibition What About AIDS?: Science, Art & Human Stories. FireOrgan, which provides a place for the public to reflect and contemplate, is featured at the Exploratorium from March 5 to June 2, 1996. The FireOrgan project is made possible by AT&T: New Experiments in Art & Technology.

As visitors enter FireOrgan, they trigger photoelectric cells or pressure-sensitive floor mats, causing the flames to create air pressure in the organ's resonant chambers. As with a conch shell or any organ, the sounds produced by FireOrgan are dependent on its resonant chambers--in this case, free-form, hand-blown glass tubing of different colors. The flames, which change from white to blue as each note is played, and the airflow within the tubes are the source of the sounds. While the flames flutter at their own frequency, bursts of air rise through the tubes, producing sounds.

As FireOrgan's flames grow hotter, short bursts of gas ignite and extinguish to produce a sound similar to that of a bass drum. Steady flames produced in glass tubes of various lengths create low, chantlike notes with deep, resonating frequencies. Meanwhile, the vibrating glass rings out so that visitors can hear individual pitches.

Although FireOrgan creates acoustic sounds through the interaction of flame, air, and the tubes, it also involves the latest technology: a Macintosh PC controller and solenoids activate the flames, which respond to a visitor's presence. The controller also synchronizes the pitch of human voices: as visitors sing or speak into microphones, they create a conversation of sympathetic resonating frequencies with the singing flames.

Trimpin's installation at the Exploratorium is part of SoundCulture 96, the third international festival of contemporary sound practices, which San Francisco will host in April.

Physicists' experiments with the relationship between resonating frequencies of flames and voices date back to 1777, when a Dr. Hoggins noted the sounds a gas flame produced. Then, in 1857, Count Schaffgotsch experimented with "singing flames." When Schaffgotsch raised his voice to the proper pitch, he noticed that a flame that had been burning silently in its tube began to "sing."

He discovered that when the end of a twelve-inch tube is placed about one and a half inches from a flame, the flame trembles but does not sing. However, when the tube's distance from the flame is doubled, sound is produced. Between these two positions, the flame burns silently, but a voice will cause the flame to start singing, and this will continue even when the voice stops.

Professor John Le Conte, Schaffgotsch's contemporary, made a similar observation while attending a music performance. "Soon after the music commenced, I observed that the flames in the gas-lit wall sconces exhibited pulsations which were exactly synchronous with the audible beats," Le Conte wrote. " It was exceedingly interesting to observe how perfectly even the trills of the instruments were reflected on the sheet of flame. A deaf man might have seen the harmony." Then, in 1873, physicist G. F. E. Kastner developed a keyboard-sized "Pyrophone," which W. Weissheimer, a pupil of Franz Liszt, used in one his compositions. Since then, there has been no record of any use of fire as a source of music.

Trimpin's work is an ongoing exploration of sound and vision and how they combine to cross the threshold of perception. He is known around the world for creating automated and often whimsical sound-producing sculptures that bring together natural elements--water, air, fire, light, and computer/MIDI equipment, the latest technology available.

His sounds extend our understanding of nature and what we thought possible, yet are always completely acoustic. Installations or performances of his work have been held at the Lincoln Center, home of the New York Philharmonic Orchestra; the Walker Arts Center in Minneapolis; throughout Europe; and in many other venues.

Trimpin's sound sculptures often juxtapose the past, using methods that may be ancient, in tandem with the development of his own technology. He may demonstrate a tuning system that may be a thousand years old, for example, or--in this case--the history of sounds produced by flame.