General Vo Nguyen Giap, the military genius behind the Communist victory, was there. He is 82. There too was comrade Nguyen Van Linh, 83, looking like a Confucian sage. As much a realist as a diehard Marxist-Leninist, Mr Linh, a former party leader, was responsible in 1986 for reversing the collectivisation of farms and factories that brought Vietnam to the edge of starvation. Now retired, Comrade Linh snipes at the party leadership in press articles. He warns his own "open door" reforms have opened the door too far, too fast, letting new economic imperialists - and corruption - creep back into Vietnam.
Mr Linh undoubtedly noticed that even in the liberation parade capitalism reared its dragon's head. A troupe of gymnasts, holding a long-tailed dragon that snaked through the parade of workers and youth brigades wore costumes bearing the brand name of a foreign company. By Asian standards, it was a small, homely parade. Just a few thousand "fellow citizens, comrades, friends and combatants" were invited to watch; the route around the old presidential (now Reunification) palace was sealed off from the rest of the city by police who feared a few "counter-revolutionaries" might act up.
The parade's route to the palace paralleled that taken on 30 April 1975 by a lone Soviet-made tank from the North Vietnamese army which, after getting lost in the city and having to ask directions, bashed straight through the presidential gates. The tank fired once, and South Vietnamese officers who had gathered for a ceremonial surrender on the palace steps scurried back inside.
This time there were no Russian tanks in the parade, only a great number of papier-mch electricity pylons symbolising progress, or at least something to plug into for all those trying to buy television sets.
After several hours of earnest revolutionary songs, someone put on the kind of music you would hear in Ho Chi Minh's two hottest discos, Planet Saigon and Apocalypse Now. It was time for General Giap and the others to leave, as at a party when the younger set, tired of their parents' waltzes and polkas, commandeer the record player and turn up the volume. For the venerable old comrades and Mothers of the Revolution, it had all become too loud and strange. They looked as if they wanted to be taken home.
Like the deafening rock music, there is much about the new Vietnam some party leaders do not like. For old-timers such as General Giap and Mr Linh, it all seems to be veering off course.
Capitalism as such does not worry them; in Vietnamese families you will often find a happy mix of Catholics, Buddhists and one or two other cultists thrown in, so there is no contradiction for them in "capitalist- communism".
What distresses them is that the country may lose its identity and economic independence, won back back at the cost of more than 3 million lives in the war against the Americans, and the French before them.
As Ho Ngoc Nhuan, a former resistance fighter, said: "We're worried that the young today may forget our sacrifices and think only of new Honda motor-scooters."
General Giap, for one, was concerned enough to take a break from his daily exercises and his readings in military history and fly to Ho Chi Minh City recently, where he met a group of intellectuals over a private dinner. One participant, Nguyen Phouc Dai, a lawyer, said the general expressed dismay over the rapidity with which such Western imports as individualism and consumerism were corroding old socialist values. "He was of the opinion that our morality was being dissipated, that we were losing respect for our fathers and the way of our ancestors."