In a fourth-floor rehearsal room at the Dorothy Chandler Pavilion this week, David Cossin picked up a black rubber flip-flop, its toe thong removed, and whacked the top of a hollow plastic tube immersed in a water-filled cylinder. As he raised and lowered the tube, the sound he produced changed pitch. The effect was unexpectedly alien and visceral.
L.A. musicians Theresa Dimond and Tom Raney watched. Then Raney lifted his own modified flip-flop and followed suit, experimenting with pitch levels and strike force.
The wooden floor below -- already wet from similar exercises involving plastic cups, empty squeeze bottles, salad bowls and fingers -- got wetter.
Despite appearances, these antics weren't child's play. Looking on, Los Angeles Master Chorale music director Grant Gershon interjected questions about tempo and timing as lead percussionist Cossin guided Raney and Dimond through the first splash-through of their parts in composer Tan Dun's "Water Passion After St. Matthew." The Master Chorale will present the work's Los Angeles premiere Sunday and Tuesday at Walt Disney Concert Hall.
Based on J.S. Bach's monumental retelling of the Last Supper and the crucifixion, the piece was commissioned by conductor Helmuth Rilling and the Internationale Bachakademie in Stuttgart, Germany, for the 250th anniversary in 2000 of Bach's death. It is shaped and framed by water -- visually and aurally, as ritual and as metaphor -- in an exotic melding of Buddhist and Christian beliefs and ceremonies and of Asian and Western musical traditions.
"This is one of the most devastatingly emotional readings of the Passion narrative that I know of in all music," said Gershon. "Lord knows, enough composers have done this over the last 400 years, and yet I think where this piece takes us really does unlock new emotional territory and new resonance.
"It really is different in any performance. A lot of it happens spontaneously or is improvised. It takes us all to places that we're not used to exploring in ourselves as performers."
The multifaceted piece is a puzzle to some, concedes New York-based Tan, an Oscar winner for his "Crouching Tiger, Hidden Dragon" score. "When you are inspired by all kinds of culture, people sometimes are not so understanding," he had observed by phone a few days earlier. " 'Why are you writing the Passion story, inspired by Buddhism?' My answer is, 'Why not?' "
The Christian story of suffering, hope and rebirth, he feels, resonates across cultural barriers. When biblical texts are set to the music of Tibetan instruments and ancient Buddhist sonorities are set to biblical texts, "it is no longer a church service, it's a universal drama -- a sharing, a ritual of cultures."
Much of the water music in the piece, Tan explained, was inspired by "water splashing festivals," an ancient tradition held each spring in his native China, and by his childhood in the villages of Yunnan. The rivers in the southern province are central to daily life, places to bathe, wash vegetables and launder.
"In the afternoon," he said, "when people washed clothes in the river, they used stones and big wooden sticks and banged the clothes in the water. They made beautiful rhythms."
The gentle water sounds that signal "Baptism," the beginning of "Water Passion," were inspired by an even more personal experience: Tan's being with his wife during an ultrasound test when she was pregnant with their first child.
"I heard this water world," he said. "And I realized that this sound, this water world, is everybody's experience before they come into this life."
Still, the overt theatricality of his vocal, acoustic, electronic and organic "Passion" is among the places less explored by classical singers and musicians. The 90-minute work is meant to be seen as well as heard. Its 17 translucent, illuminated, amplified water bowls, set atop black cylinders arranged in the shape of a cross, aren't the only staged element.
The singers -- including the featured soloists, soprano Elizabeth Keusch and bass Stephen Bryant, who performed in the Stuttgart premiere -- must walk and move about. They are also required to play Tibetan finger cymbals, click and pound stones together and dip their hands into the bowls.
Vocally, they're called upon to combine Western-style classical singing with the non-Western drone chant of traditional Mongolian overtone singing and the swooping extremes of Chinese opera.
The overall effect is "what Tan Dun calls vocal calligraphy," said Gershon, who learned special hand gestures to cue the singers.
"It's liberating," said Master Chorale member Alice Murray. "There are times when it feels like you're just channeling the most ancient sounds. It's like you're not performing, you're not singing, you're just releasing something that existed way before you did. It's pretty overwhelming, very primal."
The visual quality of the piece extends to the sheet music. Squiggles tell percussionists to create streams of bubbles with soda bottles and empty ketchup containers; Xs and dots can mean "a meditation of drips" or a "storm" of splashing, Tan said. Written prompts tell musicians and singers when to walk from one place to another, and musical notation enclosed in a circle indicates a chanted vocal passage "with no beginning and no end."
"This is a piece that creates its own universe," Gershon said, "and because of the incredible focus that is required from performers and audience alike, we perform it straight through, with no late seating and no intermission."
Cossin, who has worked with Tan for more than a decade, has performed all but one of the "Water Passion" concerts. He will return to Disney Hall at the end of April for another of Tan's "organic" compositions, "Paper Concerto for Paper Percussion and Orchestra," with the Los Angeles Philharmonic.
A composer of experimental music and a creator of sonic installations as well as a percussionist, he likes the unpredictability inherent in Tan's use of water as an instrument and a resonating chamber.
"You may try for a certain sound and something else will happen," he said. "There's always that sense of being in the moment and reacting to what you're hearing. There's a lot of freedom to the piece in that way."
But it's a challenge to create sounds that are "ethereal and otherworldly, sounds that don't remind you of something else," said Dimond, who managed to stay relatively dry during rehearsal, even when hoisting a giant sieve out of the water bowl in front of her and holding it high to create a cascading waterfall.
The drawback is that "so much time goes by while you have to make all of these lovely, frolicking sounds, you could easily lose your place in the score."
"The other challenge," Raney said, "is to not knock over the water bowls."
The performers aren't the only ones who might be in for a dampening.
"A warning to the audience in the first couple of rows," Gershon said. "Maybe bring a raincoat. Things do get a little wet."
Los Angeles Master Chorale
Where: Walt Disney Concert Hall, 111 S. Grand Ave., L.A.
When: 7 p.m. Sunday, 7:30 p.m. Tuesday
Price: $19 to $79
Contact: (800) 787-5262 or www.lamc.org