Vladimir Horowitz today gave his first performance in his homeland of Russia in 61 years. And when it was over, the audience at the Moscow Conservatory rose with a thunderous and moving eight-minute ovation, greeting him as a long-lost son.

For two hours, Horowitz sat at the Steinway piano he had brought from America and, with a touch and a strength that belied his 81 years, played a program of 19th-century romantic compositions.

The audience was enthusiastic about the Scarlatti, captivated by the Chopin and the Liszt. But when Horowitz played selections from the Russian composers Scriabin and Rachmaninoff, the crowd erupted with bravos and emotion.

Here before them was one of the world's greatest pianists, born in the Ukraine, who made his name in St. Petersburg, left the Soviet Union at the age of 20 and now had come back in his old age to play for them.

But what was most important here was that Horowitz was bringing back to Russia a style of play that was once distinctly Russian and has now all but vanished.

That style, expansive but controlled, and above all evocative, has been replaced by an emphasis on technique and, as one music student put it, by "volume."

Horowitz's roots are in the 19th century, along with those of the composers whose works he chose to play. Born in 1904, he was a friend of Rachmaninoff, and as a child he played for Scriabin.

"He has brought us back a way of playing that is forgotten here," said one young Soviet composer today. "We invited him here, and he brings us our own music. It is sad."

"There were only two people who could play like he does -- Horowitz and Rachmaninoff, and Rachmaninoff is dead," said pianist Vladimir Feldsman. "I just thank him for coming back and playing to us."

Horowitz -- or Gorovitz, as his name is pronounced here -- needed no advance billing. Although his tour was announced in the papers two months ago, there were no notices for the concerts. But tickets for today's concert sold instantly when they appeared a week ago. Word that last Friday's dress rehearsal would be open to the public spread like wildfire and crowds pressed past uniformed police and rushed up the stairs.

Today again a group of people without tickets managed to get past barricades and lines of police outside the conservatory. They literally crashed their way past the ushers, up the grand staircase to the top floor, where they lined the overcrowded gallery. Witnesses reported scuffles with police.

While Horowitz was playing inside, outside in the cold spring rain stood hundreds of admirers who had come early in the vain hope of getting a ticket and who stayed late to catch a glimpse of the great pianist leaving in his black Chaika limousine.

The Bolshoi Zal (Great Hall) of the conservatory seats about 1,800 and today's audience was estimated at well over 2,000.

Below in the orchestra seats were ranking members of Soviet culture, including a deputy minister, well-known actors, poets, composers, ballerinas and foreign diplomats. Soviet Foreign Minister Eduard Shevardnadze's wife Nanuli was there, but in an unofficial capacity. But it was to the gallery that Horowitz directed his attention, waving a white handkerchief, smiling and making faces.

During the concert, as during other appearances here over the week, Horowitz has charmed reporters, fans and colleagues with his playful manner, spoofing both himself and his audience, mugging for the cameras. (A documentary of his tour was filmed for American and European audiences, and the concert was shown with a two-hour delay by CBS' "Sunday Morning" in the United States.

Tonight, at a dinner in his honor at the residence of U.S. Ambassador Arthur Hartman, Horowitz tapped his knife and fork on his plate, in time to a rendition of music from Bizet's "Carmen" by a group of Russian balalaika players.

At the dinner attended by about 200 guests, Horowitz said the audience's response today had been "very good." "People are very sweet to me here," he added.

The Moscow concert is one of two that Horowitz will give here. The other is to be held in Leningrad next Sunday.

The Friday rehearsal was in some ways a more intimate, more powerful performance. But in today's concert, as he warmed to the program, Horowitz seemed, as one Russian put it, to let "his soul play."

"He is from another world," said Alexei Batashev, a jazz musician and concert producer. "Fantastic," said Nanuli Shevardnadze. "He has a great presence."

"It is not human, it can only come from heaven," said Mikhail Dolberg, husband of Horowitz's niece, who came from his native Ukraine to be with her famous uncle.

Horowitz's tour in the Soviet Union -- which began on April 15 and will end April 30 -- is one of the major events since the signing of U.S.-Soviet cultural agreement last fall.

At a press conference last week, Horowitz said the cultural agreement was a key reason for his decision to return to the Soviet Union after so many years of self-imposed exile.

"First there was war for 30 years, then I had so many concerts to perform, and then I didn't play at all for 10 years. That's how the time has passed," he said.

At the press conference, he mixed English and Russian to the point where his interpreter had trouble keeping up with the switches. He rambled on about how his mother wanted him to play Bach and not operatic tunes; how Scriabin, when he met Horowitz as a child prodigy, advised him to be not only a great pianist but an intelligent person as well.

On other points, Horowitz was pithy. He disputed the theory that he belongs to the Russian school. "I am from an international school, not Russian," he said. On when he will retire, he said, "Somebody from above knows that better than me."

About Moscow, he said he remembered little. But he noted with some bemused pride: "I saw Lenin alive in Moscow. And in Kiev, when I was 9, I saw Nicholas II."

But he was at his warmest when he talked about his feelings about returning here. "The most important is to see people and to talk, because playing, well, to play is the same everywhere -- Moscow or New York. And only here do I have relatives."

He is staying at the U.S. ambassador's residence and gets up each day at noon to practice. But Horowitz's tour here has been something of a pilgrimage. He has been to visit Scriabin's apartment, now a museum, where he played at the composer's piano and brought tears to the eyes of Scriabin's daughter Elena Scriabin, now 84. She had last seen Horowitz in 1925 on a Black Sea cruise.

Another stop will be to Tchaikovsky's house in Klin. As it now stands, a trip to his home town in Kiev has been ruled out.

According to his niece's husband, Horowitz has delighted in talking about his family in Kiev -- "not about the deaths, just about the past, the way it was," said Dolberg.

Tonight, after prolonged applause, Horowitz gave the crowd three encores -- pieces by Schumann, Moszkowski and Rachmaninoff. When he was done, he rose from the piano, paused, stooped to pick up a flower from the scores of bouquets at his feet, and walked off stage right, twirling the rose slowly but with flourish.