Mr. Stern had a career that could only have been born in the 1960s. Trained as a painter, he met future partner Jackie Cassen in the mid-60s. They began experimenting with light and were soon asked by LSD guru Timothy Leary to collaborate on the latter's "Psychedelic Celebrations."
Describing one such show, set in a former Yiddish Theatre on Second Avenue, Mr. Stern said, "Our marquee, 'Psychedelic Celebrations and the Death of the Mind,' replaced Ben Bonus and the Yiddish Follies. On that night, there were thousands of people and thousands more out on Second Avenue. Of course, the audience was high. They came in high and they left higher. It was that time when everything was fresh—no violence in the air, no aggression."
Around the same time, Mr. Stern created "experimental light environment workshops" with Joseph Chaikin's Open Theatre, light shows for The Doors, The Byrds and The Rascals, and created 3,000 images to accompany Igor Stravinsky's "The Rake's Progress." Later, he created neon signs for the Broadway musical Kiss of the Spider Woman, and work for shows by Laurie Anderson.
In 1972 he and Charles Schwartz founded the Soho galley Let There Be Neon (now located on White Street in Tribeca). There they resuscitated the lost art of neon imagery, which has fallen into decline after its heydey in the 1920s and '30s, creating art-oriented installations as well as more prosaic signs for bars and restaurants.
Mr. Stern—a long-haired, rangy presence redolent of the decade that birthed his career—returned to the theatre in 1999, creating Theatre of Light, a wordless, plotless light show which had a run at the Flea Theatre and later played in New Jersey. In the visual fantasia, which involved 36 projectors and more than 5,000 hand-painted slides, Stern cast his visions of swirling light upon four rotating, circular screens of various sizes. Accompanying the slightly hallucinogenic presentation were a series of eclectic musical selections. "It's theatre because the intention of theatre from the beginning, which is long lost now, is magic," Mr. Stern said at the time. "Magic is an essential component of theatre. It's the space in which unexpected things can happen on a human scale."