In Siberia, 100 miles south of the Arctic Circle, scientists are trying to create a pre-Ice Age ecosystem by populating a remote location with moose, wild horses, and reindeer. Within a place known as Pleistocene Park, no one can predict the result. The goal is to bring in modern analogs for long-extinct mammals and then watch and learn.

In Rochester, musicians and teachers are creating a cultural ecosystem with a similar purpose. They're populating the city with instruments, specifically, with a collection of new and historic organs they say is unparalleled in North America.

The Eastman Rochester Organ Initiative (EROI) has produced two rare creatures so far. The first is the elegant Italian Baroque organ in the University of Rochester's Memorial Art Gallery, a kind of gilded saber-toothed tiger with a warm, pure sound. The second is the equivalent of the wooly mammoth. It is a duplicate of an old instrument found gasping its last asthmatic breaths in Lithuania.

This week Eastman will debut the 30,000-pound Craighead-Saunders Organ in Christ Church on East Avenue. The instrument's creation took eight years of research and building on two continents.

"It's a dream. I can't believe we're there," says Hans Davidsson, an organist and director of EROI. Davidssohn spearheaded the project after working on a similar one in Sweden.

"We are creating the best venue for the performance of the music of J.S. Bach and other 18th century sacred Germanic music anywhere in North America," he says.

Eight years ago, Davidssohn was approached by a Lithuanian man with a strange request. Since the late 1960's, the man had been guarding an organ in a Polish church in the town of Vilnius, protecting it from alteration by well-intentioned preservationists. Built in 1776 by a then-famous organ builder named Adam Gottlob Casparini, it was in near-original condition, miraculously having escaped the bombs of World War II.

But the organ was in bad shape, leaking air during Sunday services. Davidssohn agreed to go and take a look.

"It was like walking into history," he says of his first trip to Vilnius. "It was mind-boggling to see this instrument still being played for Sunday services from 7 in the morning to 9 o'clock at night with people singing all day long. The organists came in shifts."

Davidssohn suggested more than just restoration. He arranged for technicians to measure, photograph, and document the Casparini organ and then build an exact duplicate of the 2000-pipe instrument in Rochester.

To accomplish this, five teams of organ builders took several years to study the instrument. They agreed to duplicate every detail of the original without question, even those touches that might seem superfluous or merely ornamental. For example, they painted old-style Germanic script inside the case of the new organ to indicate the note played by each pipe.

"By doing this, [organ builder] Munetaka Yokota got a sense of gesture that helped him recreate the speech characteristics of the original pipes," says Davidssohn.

In reproducing the instrument without questioning the original design, Davidssohn says, builders have learned things about organs they couldn't have anticipated.

The finished instrument rises 24 feet high and 25 feet wide from a balcony 12 feet above the sanctuary in Christ Church. (Meanwhile, the Casparini organ in Lithuania lies in pieces; Davidssohn is hoping it might be restored in the next couple of years.)

Hundreds of musicians, scholars, and builders from countries including England, Japan, Australia, and Lithuania will attend a five-day festival in Rochester celebrating the Craighead-Saunders Organ's completion.

"I couldn't get a ticket," says Ron Fabry, Dean of the Rochester Chapter of the American Guild of Organists. "I waited until the last minute."

Fabry says the EROI project has inspired a boom in organ construction throughout Western New York. Recently, he played for a wedding on the new Halloran-All Saints Organ in Rochester's Sacred Heart Cathedral. It has a flat pedal board, and when he tried to put his heel down to play a note, he almost slid off the bench.

"These organs are teaching us something about how music sounded," Fabry says. "They're giving us a whole different view of music."

Davidssohn said the mammoth Craighead-Saunders Organ at Christ Church will help his students develop understanding and techniques they could not learn on a modern instrument.

"It was a one-of-a-kind opportunity," he says, "and the beginning of a new journey of discovery into the music of J.S. Bach."

Brenda Tremblay blogs about music at wxxi.org.

2008 EROI Festival

Christ Episcopal Church, 141 East Ave. (and other venues)

Thursday, October 16-Monday, October 20

Free-$30 | 454-2100, esm.rochester.edu/EROI