After an absence of 61 years, Vladimir Horowitz, the legendary virtuoso pianist, came back to his native Russia today for a two-concert tour that already has the Soviet music world spellbound.

Horowitz, who at 81 rarely gives concerts anywhere, arrived with his entourage at Moscow's Sheremetyevo Airport and in an impromptu press conference held half in Russian, half in English, proclaimed himself an "ambassador of peace."

His two concerts here, the first to be held in Moscow next Sunday and the second in Leningrad a week later, are expected to be the main musical events of the year and are a major achievement of last November's new U.S.-Soviet cultural agreement.

Horowitz left the Soviet Union in 1925 on a six-month visa to test his talents in the western world, knowing the break with his homeland -- a homeland he regarded in bitter terms -- was virtually permanent. "I have no desire to return," he is quoted as once saying. "I don't like the Russian approach to music, to art, to anything . . . I never want to go back and I never will."

Today Horowitz -- or Gorovitz, as he is known here -- made his way through a throng of cameras and reporters. He was pale and slight, dressed in a black hat and overcoat and carrying a black umbrella that still had a baggage claim check on its handle.

"I came back," he said, discounting his vow of many years ago. "It was wartime then. Much has changed." Later he added, in Russian, "I had to come and see what is going on here now. I don't know what is going on here now."

Shielding his eyes from the glare of the lights, he obligingly sat in the VIP lounge and answered reporters' questions, reluctantly at first when they were put to him in English, more playfully when he started speaking Russian.

Asked how he felt to be back after so many years, he shrugged. "Numb," prompted his wife, Wanda Toscanini Horowitz, daughter of the famous conductor.

He showed a youthful eagerness and curiosity about his old world, said he planned to go to the theater and opera, to see friends and even to return to his home city of Kiev, but only if he could do it in one day.

Here to meet him were Oleg Smolenski, head of the Soviet state concert organization, or Goskoncert, and other Soviet cultural officials, U.S. Ambassador Arthur Hartman and his wife Donna, and Horowitz's niece Lena Dolberg and her husband Mikhail, who had come from the Ukrainian city of Kharkov for the occasion.

Lena Dolberg had last seen Horowitz in 1925, when she was 6 years old and he was "young, beautiful and happy," as she put it.

Despite the long absence, the distance and the differences of their worlds, the great pianist and his niece quickly got down to family affairs, talking about relatives back in the Ukraine, dinner plans and trips.

"Volodya" was the way his niece addressed him -- the common nickname for Vladimir and the name by which he was known when he left the Soviet Union in 1925, then 21 and already famous.

According to one biography, Horowitz was already so popular in Leningrad during those bleak years after the Russian Revolution that he had an official fan club known as the "Green Girls."

The music of Chopin, Liszt and above all Rachmaninoff suited his style, which was representative of an older, now dying school of Russian music that emphasized feeling and bravura.

Born to a musical Jewish family in Kiev, capital of the Ukraine, Horowitz began his career before the 1917 revolution. He arrived at his first concert in Kharkov by horse and carriage, dressed in the black trousers and open-necked white shirt that were standard concert attire in czarist Russia.

He later moved to Leningrad, an intense, high-strung young man who began to develop a flair for artistic eccentricity. But fame in Russia, then and now culturally isolated, was not enough. "We were all famous in Russia," said Horowitz later, "but when we finally came to Berlin nobody knew who we were."

Arrangements for Horowitz's visit have involved not only Goskoncert officials, but also staff at Spaso House, residence of the American ambassador, where the pianist will be staying.

Horowitz apparently insists on a daily diet of fresh sole, asparagus, artichokes and other vegetables that are virtually impossible to find in the Soviet Union. To accommodate him, some food has been brought specially, as have his favorite movie videos -- such as "Zulu" and "The Changeling."

"This will be the crowning of the season," said Oleg Smolenski. "There has been colossal interest. Phones at Goskoncert are ringing without stopping."

Tickets for his first concert, at which he will perform a program including Rachmaninoff, Scriabin, Chopin and Liszt, sold out immediately on Sunday. Of the 1,793 seats in the concert hall at the Moscow Conservatory, only 424 were actually put on sale; the rest are reserved for the elite of Moscow's cultural and musical world.

The scramble for tickets is just one indication of the awe in which Horowitz is held here. Mikhail Dolberg, his niece's husband, explained that Horowitz's memory has been preserved among the older generation and that younger musicians are fascinated by him as a survivor of an earlier, more romantic era when style reigned.

There is also the appeal of the triumphant return of the native son. "It is his homeland," said Dolberg. "It is just too bad that he was so late in coming back."