Hundreds of white porcelain bowls drift across three circular pools in the heart of Athens, gently colliding to produce a shimmering, ever-changing chorus of bell-like notes.
On Sunday, anyone can step in to listen for free.
The installation, "clinamen," by French artist and composer Céleste Boursier-Mougenot, will open its doors without tickets on Nov. 1 at Onassis Mandra.
The free day was timed for the eve of International Stress Awareness Week.
The work has drawn crowds at the Bourse de Commerce in Paris and the Park Avenue Armory in New York.
In Athens, it is being shown outdoors for the first time, in a restored 1909 open-air theater near the Acropolis. It is the only surviving example of the city's Belle Epoque outdoor stages.
Here, wind, birdsong, voices from the street and even rain become part of the score. Each bowl was chosen by the artist for its particular tone, and the water is kept at about 30 degrees Celsius (86 Fahrenheit) to help carry the sound.
"I am interested in giving shape to visitors' senses, offering them direction but also room to daydream," Mr. Boursier-Mougenot said. "The only message I want to convey is an invitation to inhabit a space I have designed especially for them."
He first created the piece in 1997 and has since staged more than 20 versions.
Its name comes from the ancient idea of the "swerve," a concept in Epicurean philosophy describing the unpredictable deviation of atoms that leaves room for chance and freedom.
The installation has no beginning or end, and no two visitors hear the same thing. Every collision creates a new sound.
It will run in light rain but may pause in severe weather.
With storms forecast for the weekend, visitors are advised to check the ticket line, 219 2191000, before going.
By Katerina Poulopoulou