Preview: Qatsi Trilogy Live, Wales Millennium Centre, Cardiff

It's life - but not as we know it

It was in 1975 that the monk-turned-film-maker Godfrey Reggio decided to make "metaphysical films". He'd spent the previous 14 years in silence and prayer as a member of the contemplative religious order the Christian Brothers. Now the fame of Reggio's Qatsi Trilogy precedes him. He describes the work as essays of visual images and sound, which document "the metamorphosis of old nature to the new technological world. My films are not aimed at the mind, but at the solar plexus.

"I was working with street gangs and delinquents, and I saw Luis Buñuel's Los Olvidados (The Young and the Damned) and I had a spiritual experience," he recalls. "I decided that I would like to use film to express the sensibility of facing this world; not psychological films, but metaphysical in nature."

Reggio had a hard time convincing Philip Glass, the composer, to create the music for his debut film, Koyaanisqatsi, released in 1983 (the title is a Hopi Indian word meaning "life out of balance"). "But when I showed him some preliminary footage, it blew his mind," says Reggio. The trilogy, which includes Powaqqatsi ("life in transformation") and Naqoyqatsi ("life as war"), will be screened while Glass and his ensemble perform live accompaniment under the conductor Michael Riesman.

The film's role, says Reggio, is "to provoke, to raise questions that only the audience can answer". He likens the experience to watching a sunset. "If you were looking at a sunset, you wouldn't ask me: 'What is the meaning?'" he says. "It would be a stupid question. It could be meaningful. So I have tried to create a meaningful experience in my films. This is the highest value of any work of art, not predetermined meaning, but meaning gleaned from the experience of the encounter."

Reggio is looking for funding for Savage Eden, "a comedic cinematic opera" that will be his first film to feature actors.

Wednesday to 2 December (0870 040 2000; www.wmc.org.uk)