MOSCOW - Some of the world's most gifted young musicians are wearing overcoats to class and trying to read sheet music by window light after a fire roared through three classrooms at the venerable Moscow State Conservatory.

As aspiring performers and composers took final exams this week, there was no electricity, limited telephone service and a trickle of heat from an emergency system. A week after the Dec. 17 blaze, 16 precious concert grand pianos sat damaged or destroyed. Bundles of canvas hoses still dangled from the stairwells, and the air stank of soot.

Still, the melodies of Brahms and Haydn rang through classroom halls again after days of uncertainty and confusion.

A ferociously intense Juri Bashmet, a Conservatory-trained violinist and conductor, led an orchestra in a rehearsal of a Baroque symphony in the Great Hall, which seemed to swell with warm, rich sound.

Students said they were grateful to be back in class.

"At first I simply couldn't believe it," said Ilya Ovchinnikov, a 19-year-old piano student from Moscow. She had left the school the afternoon of Dec. 17 and later watched firefighters battle the blaze on television. "For me, this is still some sacred place. I could never imagine that a fire would start here."

It could have been much worse, conservatory officials say. The chrome-yellow gingerbread mansion - a short stroll west of the Kremlin - could have been reduced to char and piles of bricks. Instead, the blaze blackened only a small portion of one wing of the building, and all classes had resumed by early this week.

Facing major repairs

But conservatory officials say the fire has forced them to start planning major repairs to the historic structure.

"We realize that the situation is very serious, and may even be dangerous," said Ksenia Ilyina, a spokesman for the school administration.

The Moscow State Conservatory and the St. Petersburg Conservatory are considered Russia's leading schools for composers and performers. The Moscow institution's graduates and teachers include Peter Ilich Tchaikovsky, Sergei Rachmaninoff, Alexander Scriabin and Dmitri Shostakovich, as well as performers such as Mstislav Rostropovich and Bashmet.

Russian composers have been staging premiers of their work at the Moscow school since 1879, when Tchaikovsky's Eugene Onegin was first performed there. The Canadian pianist Glenn Gould, then 24, became the first North American musician to appear in the Soviet Union when he played his distinctive interpretations of Bach at the Great Hall in 1957. The concert made him an instant celebrity behind what was called the Iron Curtain.

Despite its prominence, the conservatory has seen little restoration work since World War II. Rector Alexander Sokolov called the blaze inevitable, given the decrepit state of the wiring.

"It could have happened anytime and anyplace in the structure," Sokolov said, standing in his dark office, which is decorated with portraits of his predecessors and a badly worn oriental carpet.

"The building is over 100 years old. It needs complete renovation - including foundations, electrical and heating systems. Previously, there was cosmetic work, which of course was not enough."

Older than Peabody

The Conservatory was founded in 1866, two years before the Peabody Conservatory was born in Baltimore. The Moscow institution moved to its present location - the former palace of the Vorontsov family, one of Russia's richest and most powerful - in 1871.

The fire, started by an electrical short in a second-floor classroom, was confined to part of a wing of the mansion adjoining the Great Hall, which suffered no visible damage. Neither did the Small Hall, used for intimate chamber concerts.

But water used to fight the blaze caused much wider destruction. It flooded several floors, including the school's library, where some historic letters and manuscripts were soaked.

Flooding caused plaster to strip away from the walls and whole sections of flooring to buckle.

Worse, Conservatory officials say, the water undermined the mansion's wooden foundations, weakened its walls and stripped the remaining shreds of insulation from its electrical system, installed in the 1940s.

Damage assessment

The full extent of the damage will not be determined until a hastily assembled committee makes its report, Sokolov said.

But fixing the fire-scorched classrooms alone will cost more than $600,000, another school official estimated. If the school's six damaged Steinway pianos cannot be repaired, each could cost more than $100,000 to replace.

Like many of Russia's penurious public institutions, the Conservatory has no fire insurance.

The Kremlin probably cannot afford to pay for the repairs, much less the more extensive renovations. Although the Conservatory is a state institution, the government funds only part of the cost of running and maintaining the music school, officials said.

For example, it supplies one-quarter of the $315 monthly salary to the institution's world-famous teachers. The conservatory must scrounge the rest from donors and generous foundations.

To raise the millions of dollars likely needed for wholesale renovation, Conservatory officials are appealing to donors, such as Russia's prospering oil companies, as well as alumni in Russia and abroad.

Ilyina, the conservatory spokesman, said the school is working on plans to stage benefit concerts in several countries, including the United States, starting next month.

There will likely be benefits in New York, Washington, Chicago and possibly Baltimore, she said. (The director of the Baltimore Symphony, Yuri Temirkanov, is a graduate of the St. Petersburg Conservatory.)

Natasha Folivina, a 23-year-old viola student, said that when the fire broke out, many of her fellow students forgot to retrieve instruments, coats, hats and gloves as they dashed out onto the icy streets, where temperatures hovered around 15 degrees.

Luckily, she said, her friends lost only their clothing.

No fire alarms

There is no fire alarm in the building, and word of the fire spread slowly. One chamber music class noticed the blaze when they saw smoke billowing outside their window.

"For two days it was impossible to get inside the building," said Folivina, standing next to a cold radiator in a hallway where black extension cords snaked across the wood parquet.

"We were very scared that some instruments would be burned." So far, the only instruments reported lost are the pianos.

Ovchinnikov, the young pianist, says he was nervous until he came to class Monday and discovered that his favorite concert grand - on which he practices for three or four hours a day on class days - was untouched.

"Thanks to God, the fourth floor's piano was not damaged," said the Yamaha Foundation scholar, whose ambition is to become a concert soloist.