Goma came to a standstill yesterday as thousands of people crammed into town to watch the rebels celebrate the weekend capture of Kisangani, a strategic victory that could finish off the ailing President Mobutu Sese Seko once and for all.
For Mr Kabila, veteran of three decades of anti-Mobutu struggle, the occasion was a personal and symbolic triumph. The parade was led by officials of the rebel Ministry of Information, Communication, Press and Propaganda, each wrapped in the seven-starred flag of the short-lived Congo Republic.
In the territory he controls - at least a sixth of the country - Mr Kabila has already reinstated the post-colonial name and flag which he failed to defend against the Mobutist coup of 1965.
Another symbol of the rebel government has puzzled foreign observers. Their new official seal, stamped on all government documents, features a lion's snarling head. On closer inspection, this turns out to be the lion character from Disney's film The Lion King. Nobody has yet plucked up the courage to ask the rebels what this means.
Yesterday, wearing a stetson and a broad smile, eastern Zaire's new lion king faced his people from a plush armchair, listening to their cheers. Behind him his entourage of officials and soldiers jammed on to a large concrete podium specially constructed for such occasions when Mr Mobutu was still in charge of these parts.
For while the symbols and faces were different, veteran Zaire-watchers noted that the style was eerily the same. A tin roof sheltered the dignitaries from the tropical downpour which broke out shortly after the ceremony kicked off, almost two hours late. The townspeople stood huddled in the rain.
Rebel soldiers divided their time between whipping the crowd into line with sticks and glowering at the musicians and the people in the parade. One Kalashnikov-toting soldier, who could not have been more than 10 years old, was whisked away when too many foreign camera-lenses swung towards him.
Meanwhile, an electric organ was playing jaunty tunes in bossa-nova and quick-waltz time. The people paraded in little groups - first the staff of the rebel ministries, then other public servants, then the people of the town. There were agricultural societies, a guild of shoe-saleswomen with sneakers balanced on their heads, even a tobacco company whose representatives threw cigarettes into the crowd. Many banners had been hastily altered, the words "Congo" pasted where "Zaire" had evidently been displayed many times before.
In another echo of days gone by, the slogan for the event was "Uhuru" - Swahili for freedom - a cry heard across Africa during the 1960s as the European colonial powers withdrew. But when the cries died down yesterday, Mr Kabila returned briskly to the present, and a struggle which seems almost, but not quite, won.
Among those waving banners were members of the Union for Democracy and Social Progress, Zaire's main legal opposition group. With victory in sight, many groups are seeking to climb aboard the rebel bandwagon.
The rebels believe the peoples of old Zaire are swinging to their side. "In Kinshasa people are happy," Mr Kabila told the cheering crowd. "But people like Mobutu and his family are already packing their bags."
And, even after years of pillage, misrule and conflict, there was optimism in the air.