MOSCOW (AFP) - Russians on Saturday paid tribute to Mstislav Rostropovich, the legendary Russian cellist and dissident, at a lying in state in Moscow's musical conservatory.

A series of Moscow symphonic orchestras played musical tributes as hundreds of people, many of them young musicians, laid flowers by the open coffin of Rostropovich, who died on Friday, aged 80.

His widow, celebrated opera singer Galina Vishnevskaya, sat by the coffin with her head bowed, surrounded by relatives and friends of the cellist, including from his native city of Baku in Azerbaijan.

"He was one of the greatest figures in modern arts.... It's empty without him, a whole era has gone," said Ilya Kononov, 19, a cello student at the conservatory, after paying his respects.

It was from the same Moscow conservatory stage that Rostropovich bade farewell to Russia in 1974 when he was forced to flee to the United States by Soviet authorities.

In 1970 the cellist wrote an open letter to the newspaper Pravda defending dissident writer Alexander Solzhenitsyn, who had become the target of official abuse after receiving the Nobel Prize for literature.

The letter earned him abuse and pressure from Soviet authorities.

He made a dramatic return to Russia in 1991 to support the country's first president Boris Yeltsin in defying a Soviet military coup -- just months before the final fall of the Soviet Union.

Rostropovich was hospitalised in February for an operation on a liver tumour and appeared tired in television footage of his grandiose 80th birthday celebrations in Moscow.

His funeral service will be held on Sunday in the country's largest cathedral, Christ the Saviour, which only earlier this week staged a grandiose ceremony for the late Yeltsin.

The current edifice, a replica of the original destroyed in Soviet times, was erected in the 1990s with funds that Rostropovich helped raise.

The cellist will be buried in the grounds of Moscow's 16th-century Novodevichy convent alongside leading Russian cultural and political figures, including celebrated composer Dmitry Shostakovich, one of his mentors.

After the news of his death, tributes flowed in from around the world, including from Daniel Barenboim, musical director of Berlin's prestigious Opera, Italian conductor Riccardo Muti and French  President Jacques Chirac .

"It's hard to imagine that we will never hear his cello again," said the official Rossiiskaya Gazeta daily, one of several newspapers paying tribute on Friday to the musical talent and political activism of Rostropovich.

"It's also hard to imagine that such a rare figure in world culture is disappearing from our life and history -- an open figure who took human freedom as an absolute. These are the people who make epochs."

At the conservatory, journalist Anatoly Sorokin, 64, said: "He was a legendary figure. He was music itself.... In our hard times, we don't have many individuals like him."

A young British cellist, 22-year-old Catherine Pollard, said she had travelled to Moscow from Saint Petersburg, where she is studying at a musical academy, to honour Rostropovich.

"I wanted to come and pay my respects to my hero. He's such an inspirational man and one of the greatest cellists in the world.... His music really comes alive," Pollard said.

Nikita Valdovsky, a 22-year-old student of the balalaika, a traditional Russian stringed instrument, said: "He was a great musician and a very good person.... His music was education for the soul."