On the first night of the 27th Congress of the Soviet Communist Party, it looks like New Year's Eve. The streets are lit up like airport runways, flanked by acres of red flags. The roads are swept clear of snow, so hundreds of black chauffeur-driven Volgas can whisk through the center of town.

On Sunday and Monday, the route from the airport was busy as delegations of foreign communist and socialist parties arrived. In all, 153 delegations arrived from 113 countries. Of these, 12 are from ruling communist parties, 83 are from non-ruling communist parties, 37 are national liberation movement delegations and 21 are from socialist, social-democratic and labor parties.

This year, the foreign socialists -- mostly from Western Europe -- were given the same status as the foreign communists, a step hailed by the Soviet hosts as "an important innovation." It also fits in with Communist Party leader Mikhail Gorbachev's effort to broaden Soviet foreign policy.

Among those who did come, Cuba's Fidel Castro, who is probably the most popular foreign Communist here, Afghan leader Babrak Karmal and the Philippine Communists are the most newsworthy. Even more notable, however, are those who did not come, most prominently the Chinese who do not have party-to-party relations with Moscow.

The Gorbachev era has brought some change to the rituals of Soviet life, but so far it has done nothing to ruffle the elaborate arrival ceremony, a staple of the 9 p.m. news show.

For very important guests, the segment begins with a shot of the airport building at Sheremetevo, then one of the guest coming out of the plane, then handshakes with the welcoming Soviet officials.

Descending the protocol ladder, the television account of the ritual is simplified until, for the less prominent delegations, only a group snapshot taken in the VIP lounge is flashed on the screen.

But even here, politics can enter the picture, particularly when it involves warring Communist factions.

This year, the biggest row has been in the Finnish Communist Party. In that case, the Soviets did not invite the hard-line minority, who tried to wangle an invitation but failed. Meanwhile, the moderate majority is being housed at the prestigious Sovietskaya Hotel.

In the case of the Swedish and Spanish Communists, two factions were invited separately, and in those cases, the pro-Moscow minorities were shown on television before the moderate majorities.

Along with the foreign delegations came foreign journalists. There are 1,016 foreign correspondents accredited to the congress, along with 1,705 Soviets.

For the foreign reporters, an elaborate operation has been set up at the Foreign Ministry press center. Interviews have been arranged with experts and delegates; press conferences are to be held daily.

But most notable for the resident correspondent corps is the availability of noncommunist newspapers -- Le Monde, Il Messaggero and The Times of London -- at the kiosk in the press center lobby.

And there is even a way to distinguish journalists by ideology: Capitalists have identification cards on a blue string, Communists have red string.

Despite the hoopla, life for most Muscovites went on pretty much as normal today as the congress opened. As was the case during the 1980 Olympics or last summer's youth festival, the out-of-town shoppers who usually flood the capital's stores have been kept to a minimum and drivers have been advised to keep off the roads if their errands are not essential.

The city's harried shoppers are happy because there are more goods in the stores, and drivers are spared the noontime traffic jams on the central ring road.