AMSTERDAM — How big can opera be? Try 680 musicians and technicians, performing 15 hours of music from an opera cycle originally 29 hours long. Karlheinz Stockhausen, the bad boy of postwar German composers, world famous in the 1960s and ’70s, wasn’t shy about dreaming big: His “Licht” cycle, written over 25 years and completed in 2003, involved one opera for each day of the week. In Amsterdam, the Holland Festival is attempting the first overview of this sprawling work over three days, using for the purpose an appropriately unconventional and vast performance space — the Gashouder nightclub.

Yet Pierre Audi’s production, “Aus Licht,” a joint venture of the festival, the Dutch National Opera, the Royal Conservatory of The Hague and the Stockhausen Foundation, has transformed the colossus into intimate dramaturgy, inviting audiences into the most vulnerable corner of Stockhausen’s world. Indeed, at Friday’s opening performance, the Archangel Michael appeared onstage not as a triumphant seraphic body, but as a child grieving the loss of his parents to the ravages of war. (Stockhausen’s mother was killed by the Nazis, and his father on the front lines in Hungary.) Portrayed at times by a tenor, at other times by a trumpet or clarinet — many of the performers were conservatory students — Michael’s blurred characterization illustrated his metamorphosis from human into an angelic form.

Yet other portions of “Licht” trafficked in images of sheer terror. Bathed in deep red light, 80 wind players moved in organized rhythm as they accompanied projections of Stockhausen’s face (embodying the character of Lucifer), its eyebrows, tongue and mouth artificially contorted in real time by technicians. Unsettling, too, was the sight of 80 adolescent girls dressed in white, beckoning the character of Eve to usher in a new creation and a new race. As they exited, following Eve (dressed in feathers and sporting a flute) into a spaceship, it was clear that their subsequent musical journey could not take place on Earth; to understand the music of the heavens, one must travel there. (Stockhausen was known for listing his birthplace not as Cologne, but as a planet orbiting Sirius.)

Futurism was pervasive. A mammoth chorus of trombones and trumpets dressed in barbed wire moved throughout the room, using their instruments as ray-guns and laser beams, as extraterrestrials invaded Earth three times. After one of the soldiers fell, a haunting Pietà for soprano and trumpet brought the performance to a standstill — followed by a 40-minute synthesizer soliloquy during which Lucifer and Eve were reconciled in a refraction of death into transcendence. (Kathinka Pasveer, who worked closely with Stockhausen and remains one of his most active interpreters and champions, was the conductor.)

The epitome of the project was one of Stockhausen’s most famous or infamous works, the “Helicopter String Quartet,” first performed at the Holland Festival in 1995 and subsequently incorporated into the opera “Mittwoch.” The members of the Pelargos Quartet climbed into four separate helicopters, sporting headphones and with metronome and microphone and, while the helicopters hovered, sent their sounds at once into the cosmos and back down to earth in the Gashouder, at once alone and in the presence of the same music.

The dazzling outlandishness of “Licht” can be dismissed as trivial, irrelevant or even comical — indeed, at some points it felt like characters from Milton’s “Paradise Lost” had been dropped into an episode of “The Jetsons.” But as chamber operas become increasingly attractive in today’s musical landscape — at least in America — one might consider this massive cycle before assuming that intimacy is the key to sincerity. If anything, the message of this “Licht” adaptation was that to find love and foster reconciliation, humanity cannot think small.

The Holland Festival continues through June 23, with the final performance of the “Licht” cycle beginning Saturday.