Still going strong after a month of nonstop activity, the Second World Black and African Festival of Arts and Culture (FESTAC) officially ended Saturday - but the memory is likely to linger on for years.

But it was the festival's jamboree aura, rather than its formal performances, exhibits and colloquia, which seems destined to leave a lasting mark. The main benefactors of Nigeria's extravagant gift of total black cultural immersion - offered to some 50 countries plus black communities in the Diaspora - were the performers and other participants.

And the real action was not so much in the new national theater, national stadium or parade grounds, but in the festival village where thousands of participants naturally mingled with each other and came to appreciate the rich variety of their culture.

American participation in the festival had its controversial aspects as well as a late-arriving highlight. Jeff Donaldson, the Howard University professor who headed the committee organizing American participation, had his differences with the U.S. government. He felt the Ford administration had let him down by underwriting only one charter planeload of participants, although after President Carter's inauguration another charter arrived.

Part of the problem, it appeared was Donaldson's failure to raise funds which may have reflected the black establishment's lack of interest in his ardent black-power leanings redolent of the 60s.

Symptomatic of the mood was the ostracism of a white dancer who insisted she was prevented from performing with her Detroit dance group by militant black-power advocates. Other racially mixed countries - such as Cuba and Brazil - had both white and black performers.

Nor did Donaldson take kindly to criticism in the American or Nigerian press about his efforts or those of his performers. Nigeria's Evening Times noted the American committee's failure to make good on indications that Roberta Flack, Isasc Hayes and Imamu Amiri Baraka would participate. It said, "The blacks in the U.S., torn apart by their own FESTAC politics, underestimated what the rest of the black and African world would come up with."

Unlike performances from many African countries, which put their most professional talent on display, the Americans represented grass-roots community groups. It was the committee's conscious effort to get away from the big commercial names in black entertainment - the Louis Armstrongs, Count Basies and Ella Fitzgeralds who were the superstars at the First Black Arts Festival held 11 years ago in Senegal.

Yet to many Nigerians one of the highlights of the festival was Stevie Wonder's performance at a gala evening towards the end of the festival. He came to Lagos on his own, primarily to talk to and encourage the blind in Nigeria, and had to play with a pickup band.

In a way the formal audience could claim to have been shortchanged, especially the Nigerian public which for the first two weeks was treated by security-conscious policy and troops as so many potential bomb-throwers.

But thanks to the outspoken Nigerian press, which pilloried the authorities for preventing the public from enjoying the festival firsthand, empty seats at performances disappeared. From a $1.16 top, ticket prices were slashed until towards the end entrance was free.

The Nigerian government, which may have spent as much as $500 million on the festival, had good reason to congratulate itself on winding up the show so successfully.

Although conceding that critics were justified in denouncing the festival as a "gorgeious waste," the government-owned Daily Times insisted that "Nigeria is justified in feeling a sense of accomplishment." Despite the postponements, scandals and arguments over the festival planning, the newspaper said, the country "had done what many, even among its citizens, at first thought impossible."

Singled out for special attention was the festival's success in bringing together black Africans and blacks living in the Diaspora. "The aborigines of Australia, the blacks of Papus New Guinea and of Surinam may have dreamed of Africa," it said, "but they could hardly have anticipated an occasion when they would come to their ancestral home not as tourists, but as delegates to a festive gathering of the tribes."

From time to time the festival was disturbed by blatant incursions of the politics which remained just beneath the surface. No longer stateless nationalists denouncing the evils of colonialism, but citizens of often authoritarian independent regimes, the African intellectuals were sent by their governments and rarely deviated from the official line.

Perhaps understandably, the blacks in the Diaspora were more outspoken. A Brazilian intellectual teaching at a Nigerian university charged that his right-wing government had pressured the Nigerian authorities into banning his paper which questioned the official thesis of equality in multiracial Brazil.

If the festival had a queen, Myriam Makeba would have been it. Ever the consummate performer, at graceful ease as a singer and dancer, the South African-born star remained true to her role as the pasionaria of African liberation.

In the early '60s no independence ceremony marking the end of European colonialism in one African country after another seemed quite complete with her sung celebration of Uhuru.

The other night she gaily conceded that she had three grandchildren and said, "I'm getting old." She didn't show it, although the Lagos festival perhaps served to demonstrate that some of the euphoria she once symbolized has dissolved in the harsher realities of independence.