The pianist was Sviatislav Richter, one of the Soviet Union's most famous virtuosos, and after months of postponements last year, he was at last to play at the Tchaikovsky Concervatory in downtown Moscow.

The crowd grew at police barricades through, surging toward the one open on the street and suddenly pushed door. An attendant slammed it, and the crowd rolled up against the building in a tight mass for 20 minutes of chaos. A door was shattered before the wave subsided.

A few moments later, many were inside, peacfully listening to Richter, betraying no sign that they nearly trampled and probably injured some of their fellow Moscovites to get there.

Russian crowds. As a phenomenon of life here, they stand out with fierce clarity.

"Ostarozhno, deti, ostarozhno," (Danger, children, danger!) The cry rises from alarmed mothers packed breathlessly tight in a crowd struggling to leave the old Moscow Circus.

It is a cry repeated in almost any crowd at a popular event attracting children anywhere in Moscow.

To be in such a crowd - and they are common here - is to be sightless, mindless, and helpless, struggling to keep from being swept off one's feet and trampled. The crowd controls in every respect, badgered at the front by attendants who guard a single door, compressed at the back by others adding their weight to the desperate throng.

In a subway station, at a bus stop, at a hockey game, at the opera, the ballet, the circus ' the crowd threatens.

It is a subject not widely discussed in the Soviet press and so it is virtually impossible to assess the human cost of this phenomenon. In recent years, there has been public comment only once, when people were trampled to death in a crowd leaving the Palace of Sports in Sokolniki Park in March 1975.

Authoritative Western sources say 13 died as people charged down an exit ramp at the end of a hockey game between Canadian and Soviet youth teams. Moscow Pravda, the city party newspaper, reported the tragedy, but did not mention the number of victims or the reason. Western sources say the people were racing to try to barter souvenirs from the Canadians.

This is a country where people have the same hunger for goods and entertainment as they do in the West, but their wants go unfulfilled much more frequently. People habitually carry string or plastic bags with them folded in their purses or briefcases and often will automatically join a queue outside other end. For fear someone may tightly like sardines, passing word about what lies ahead.

A bus or subway stop during the busier parts of the day can be a remarkable experience. Westerners not familiar with the dense, unyielding force of a Russian crowd streaming toward a subway entrance or bus stop have sometimes been carried irresistibly along on the wave of humans.

"We've lived so close together for so long there is no sense of space or privacy as you Americans think of it," said one Muscovite, describing the impact on her psyche of growing up with her parents in a cramped two-room apartment and living there married for several years.

The queue, which adds so much to the mentality of mindlessness of a crowd, cannot be escaped once inside the theater or hall. It is prohibited to carry one's overcoat into the theater, so people queue up at coat-check rooms, where attendants, many of them elderly persons supplementing their small pensions, labor to handle the flood of coats and hats and hand over hat checks.

At intermission, people line up helplessly for refreshments from small stands in lobbies, while officious attendants carefully measure out scoops of ice cream, weighing each portion on a small scale to be sure no one gets more than the proper share. The crowd presses in, worried that intermission will end before they arrive at the stand.

Soviet crowd control methods frequently seem to contribute to the pervasive sense of oppression that can turn a mass of reasonable people into a fearsome wave of humanity. Invariably, only one entrance door is open at a heavily attended performance. Attendants, bolstered by police, stand stolidly there, demanding to see the tickets before a person can get inside to actually present the slip of paper to the proper taker.

Frequently, once the performance begins, the doors to the hall are locked shut to keep out latecomers or gate-crashers. For Westerners, the effect is to heighten the sometimes serie sense of claustrophobia and helplessness that pervades a Russian crowd.

One Western diplomat's wife took her children to a cartoon feature at a downtown movie house, not realizing the doors were going to be locked. But the "cartoon" turned out to be a propaganda attack on capitalism featuring monsters who scared her children. But there was no escape.

Such tactics simply increase, rather than diminish, the sense of blind destiny that can grip a Soviet crowd waiting outside a theater. They know they must get in before curtain time or be absolutely barred from seeing the first act. They press forward. There are hassles at the single entrance. Soon, one can barely move. There is no doubt - it is a Russian crowd.