Something astonishing has come to the Park Avenue Armory. In its Wade Thompson Drill Hall, a massive industrial cavern, two artists have collaborated in a new installation—and in doing so have created a new fluidic world.

Scottish conceptual artist Douglas Gordon and renowned French pianist Hélène Grimaud have merged their respective media in tears become... streams become..., an hour-long program that floods most of the Drill Hall floor in placid shallow water, creating a kind of double symmetry that induces pure awe. The controlled flood covers most of the hall's 55,000 square foot floor, and as the water rises through specially installed pipes Grimaud performs pieces inspired by oceans, rainstorms, and streams. As her expert renditions of Ravel, Liszt, Brahms, and Debussy ring out along the beams, the room's towering height reflects a plunging depth.

It would be mesmerizing enough to look out at this one image—the Armory's expanse duplicated by illusion— but Gordon seizes the opportunity to play with light and shadow, altering the position of fixtures and incorporating smoke. At some points in the program every detail is lit; at others all that's visible is a rippling silhouette.

All told 122,000 gallons of water make the piece possible. "I believe the emotional journey can be magnified in an exponential way," Grimaud said yesterday at a rehearsal for tonight's opening. Her beliefs are confirmed, as the Drill hall becomes a giant false double crescent, filled with revelatory music. She and her collaborator Gordon were introduced by Alex Poots, the Armory's artistic director, and began planning tears become... streams become almost immediately. But it wasn't until massive engineering problems were solved that they could realize the project.

The spectacle was made possible by dozens of technicians working to level the Drill hall's floor with shims and special waterproof panels. Both the water and room are kept at a delicately balanced temperature in order to minimize humidity and preserve the two Steinway pianos that sit inside the flood—one for Grimaud to play, the other a computerized model that plays automatically for the room's daytime visitors.

The entire piece blends elements of Merce Cunningham's Ocean with shades of David Byrne's Playing The Building and is without a doubt a must-see for anyone who appreciates having their sense of scale rattled. Whether visited during the daytime hours or experienced for full price in its live performance, Tears become... streams become... is an arresting triumph of inspiration and execution.

Armory on Park, 643 Park Avenue, Manhattan

Performances: December 9th-21st, Tuesdays & Wednesdays at 8 p.m., Fridays & Saturdays at 8 p.m., Sundays at 7 p.m. // Tickets $45-90

Installation Visiting: December 10th-21st, Tuesdays & Wednesdays 12 p.m.-4 p.m., Thursdays 12 p.m.-8 p.m., Fridays & Saturdays 12 p.m.-4 p.m., Sundays 11 a.m.-3 p.m.

Additional Visiting times December 23rd-January 4th, Tuesdays & Wednesdays 12 p.m.-6 p.m., Thursdays 12 p.m.-8 p.m., Fridays & Saturdays 12 p.m.-6 p.m., Sundays 11 a.m.-5 p.m.