With its folk-driven score and its wistful, meditative tone, “Once’’ is not your typical Broadway show. But that didn’t prevent it from taking home eight Tony Awards on Sunday night, including best musical. “The Gershwins’ Porgy and Bess,’’ which premiered at the American Repertory Theater last fall before moving to Broadway, won the Tony Award for best revival of a musical. As expected, Audra McDonald’s devastating performance as Bess in “Porgy and Bess’’ earned her the Tony for best actress in a musical. It is McDonald’s fifth Tony, and her first for a leading role. In an emotional acceptance speech, McDonald said: “I was a little girl with a pot belly and Afro puffs, hyperactive and overdramatic, and I found the theater and I found my home.’’ In perhaps the night’s biggest upset, James Corden won for best actor in a play for his uproarious, pratfalling performance in “One Man, Two Guvnors,’’ a British farce. Philip Seymour Hoffman had been expected to win for his performance as Willy Loman in “Death of a Salesman.’’ Corden also struggled with his emotions during a speech in which he called Hoffman “my favorite actor in the world.’’ Nina Arianda won the Tony for best actress in a play for her protean performance in “Venus in Fur’’ as Vanda, a seemingly bumbling actress whose audition with a playwright-director for a part in his new drama spirals into a series of mind games that end with him tied in knots, figuratively and literally. Bruce Norris’s “ Clybourne Park,’’ which manages to be both satirical and dead-serious in its examination of race relations, won the Tony for best play. When he accepted the Tony for “Porgy and Bess,’’ producer Jeffrey Richards saluted ART artistic director Diane Paulus, who helmed the musical in Cambridge and New York, as a “visionary director,’’ and called the ART “a great home to incubate’’ the production. Paulus lost out in the competition for best direction of a musical to John Tiffany, director of “Once.’’ “Porgy and Bess,’’ the story of the love between a crippled beggar and a drug-addicted outcast, got off to a stormy start last summer when the legendary composer Stephen Sondheim wrote a letter to The New York Times that harshly criticized the “Porgy’’ creative team’s description of their plans to overhaul the Gershwin opera. (The most far-reaching changes that had been considered were not in the final version of the show.) On Sunday night, “Porgy and Bess’’ defeated a revival of Sondheim’s “Follies.’’ But the big story of the evening was the success of “Once,’’ which was developed in a workshop at the ART last spring. Steve Kazee, who plays an Irish street busker who falls in love with a Czech pianist, won for best actor in a musical. “Once’’ also notched victories for best book of a musical, by Enda Walsh; best sound design of a musical, by Clive Goodwin of Arlington, the resident sound designer at the ART; and in the categories of best orchestrations, best scenic design, and best lighting design. “Death of a Salesman’’ won for best revival of a play, and Mike Nichols won for best direction of a play. In a recessionary era, there was a fresh currency to Arthur Miller’s 1949 classic about a man whose desperate, lifelong pursuit of a misguided version of the American dream ends with him being cast aside by his employer. Accepting the Tony Award, his sixth, Nichols said that Miller’s drama “does the rarest thing a play can do: It gets truer as time goes by.’’