Few who attended the concert headlined by vocalist Pery Ribeiro at George Washington University's Lisner Auditorium last fall had even an inkling that the half-dozen musicians backing up the singer were some of Brazil's finest.

Nor could any in the audience except a few of the musicians' friends have realized that, once the brief tour had ended and Ribeiro had departed for Brazil, his accompanists were determined to remain and establish themselves here. That entailed sleeping on the floors of homes in Washington and New York, scuffling for work, exhausting their savings and eventually returning to Brazil.

For all, that is, except pianist Eduardo Prates, currently in residence Tuesdays through Thursdays at Dona Flor Restaurant, where he offers a program of jazz standards, Brazilian music and originals. Prates had a special reason for wanting to become a member in full standing of the American jazz mainstream -- a reason quite apart from this Rio de Janeiro native's impressive talents as performer and composer.

That reason has to do with Prates' feeling that he spent a decade treading water, so to speak, working only part time at music. His struggles to follow his muse are the stuff of the Hollywood cliche' of the well-to-do youth with aspirations to lead the jazz life -- except that Prates' story took place not in the plush circumstances of an upper-crust American family, but in Belo Horizonte, an industrial center 200 miles north of Rio, where his father was an agronomist and his grandfather had been minister of agriculture.

Prates' early piano studies revealed that he had an excellent ear for music and could pick up tunes from radio and TV at a single hearing. But his family wanted him to go into engineering and discouraged him from thinking of a musical career.

When his skills were recognized by a big band leader one night at a party, the 14-year-old Prates pleaded with his parents to allow him to join the band, assuring them, "I will finish my engineering degree."

He never did get the degree, because he was soon caught up in the musical life. He formed his own trio, began writing music and even hired a then-unknown bass player named Milton Nascimento. But, partly in compensation for the disappointment he felt he had caused his parents and partly to supplement the perennial shortfall of the jazz player's income, Prates started a business.

At first he merely hired out his van to musicians needing to move instruments and sound equipment. Then a second van was purchased and a small freight business formed. A fleet of about 30 trucks and buses was eventually amassed. Prates' business took children to and from school by taxi, and he invested in a cheese company.

Toward the end of nearly a decade of entrepreneurial efforts, it became clear that business acumen was not among Prates' talents.

But instead of admitting failure, he tried to cover losses by expanding. He borrowed money to purchase a bus line, then bought another bus line. Teetering on the edge of and finally falling into bankruptcy, Prates appealed to his father for help. It was only through the sale of some family properties and several years of work outside music that Prates was able to resolve his financial problems.

By the beginning of the 1980s, he had immersed himself full time in the musicians' life once again. He recorded an album with vocalist Freddy Cole, brother of Nat (King) Cole, was cited by a major magazine as one of the 10 top pianists in Brazil and by one of Rio's dailies as "band leader of the year," toured Canada and Europe and came to Washington as leader and arranger of Brazilian Flavor, the Lisner program that featured Pery Ribeiro.

Felix Grant, who emceed the Lisner concert, calls the musicians of Brazilian Flavor "some of the most competent musicians you'll find in Brazil."

For those who missed the rather poorly attended concert, full confirmation of Grant's assessment will have to await the anticipated return to the United States of drummer Lillian Carmona, guitarist Romero Lubambo and the others. In the meantime, Eduardo Prates holds down the fort at Dona Flor.