WASHINGTON (AP) _ Jan Ignace Paderewski is beginning the long journey home, 51 years after President Franklin D. Roosevelt said the remains of the musician-statesman could lie in Arlington National Cemetery ''until Poland is free.''

''His life was truly a symphony,'' President Bush said in a Rose Garden ceremony today attended by prominent Polish-Americans. Bush, who will be in Poland next week to take part in the final rites for Paderewski, said it will be ''one of the great honors of my presidency.''

Paderewski's remains were lying in state today at Fort Myer Chapel, near the cemetery, before returning on a U.S. Air Force plane to Warsaw on Monday, the anniversary of his death.

Edward J. Derwinski, the secretary of veterans affairs and the highest ranking Polish-American in the government, will accompany the body.

''We have seen a decades-long struggle culminate in freedom for the Polish people,'' he said in a statement. ''It is now fitting that Paderewski's last wish, to be laid to rest in a free and democratic Poland, will be fulfilled.''

Still, the heart of the concert pianist will remain in his adopted and much-loved homeland. At his sister's request, his heart was first kept in Brooklyn, and later enshrined at the Shrine of Our Lady of Czestochowa in Doylestown, Pa.

Paderewski was regarded as the greatest pianist of his time, by the public if not by critics. His mass of white hair and his passionate manner at the keyboard helped make him the popular image of what a musical genius ought to be like.

His personality drew masses who knew little about classical music. Paderewski gave a recital in New York's Madison Square Garden to an audience of thousands, as big as those who normally went there for indoor sports events and political conventions.

During World War I, Paderewski made appeals to President Wilson that some historians credit with leading to the re-establishment of an independent Poland. The country had been destroyed by its neighbors and divided among them for 123 years.

Paderewski became Poland's prime minister in 1919. He had to resign after only 10 months in office, having failed to make peace with the new Soviet Union, and left his country soon after - never to return.

In 1939, Germans and Russians again joined to wipe Poland off the map. Paderewski became president of the Polish parliament-in-exile.

Less than two years later, Adolf Hitler sent his forces into what had been Poland, across the line he had established with the Soviets. Paderewski, 80, died in New York a week later.

Roosevelt, a friend, was at his home in Hyde Park, N.Y. He called the State Department and asked that Paderewski's remains be placed in the cemetery. They have lain incongruously ever since in a vault for U.S. sailors who died in the explosion of the battleship Maine on the eve of the Spanish-American War in 1898.

He received a funeral with full military honors, but Paderewski's body could not be placed below ground in the national cemetery because he had not fought in U.S. forces or in the forces of a U.S. ally.

Only after an indignant article in 1962 by Paul Hume, music editor of The Washington Post, was a bronze plaque erected near the vault to commemorate him. President Kennedy presided at the ceremony.

In 1975, Col. C.J. Bobinski, director of casualty and memorial affairs for the Army, raised the question of returning the body to Poland. But he noted in an official memo that ''the philosophy and ideological concepts under which the present (communist) government operates are not those of the World War II Polish government in exile at the time of Paderewski's death.''

The body was not moved.

After Poland held an election in 1990, the United States proposed returning it on the 50th anniversary of Paderewski's death. But President Lech Walesa visited Washington and said that the date would come in the midst of another political campaign and there would not be ''enough dignity in that period.''

Paderewski's remains will lie in state at the Royal Castle in Warsaw and will be taken to Poznan before burial in Warsaw's St. John Cathedral on July 5.