In the feverish world of opera, vixens are better box office draws than victims, with bonus points for being both at once.

Pure, milky victim-hood may be a surefire winner on “Oprah,” but it’s almost always a bore on the boards.

That’s one of several reasons why Michigan State University Opera Theatre’s brave production of Carlisle Floyd’s 1956 American-Gothic opera “Susannah” deserves a respectful nod.

Stripped of her feminine wiles, bleached into a symbol of innocence in a white dress, MSU’s remarkable student soprano, Elizabeth Toy, needed a heroic effort to engage the audience. By the end of the opera, cackling madly and wielding a shotgun, she got there.

Director Melanie Helton went further out on a limb with Saturday night’s performance by casting undergraduates in every role, as if to flaunt the depth of talent in MSU’s expanding opera program. She was rewarded with spirited performances from every lead.

The material was risky to begin with. Susannah, a sweet young Tennessee girl, is caught bathing nude in a creek and hounded to madness by a mob of sexually repressed, Bible-thumping townspeople. A visiting preacher rapes Susannah, but later repents, only to be shot dead by the girl’s irate brother.

The plot is overtly political, as operas go, but it falls in line with other town-without-pity sagas of the 1950s, such as “The Lottery,” “Inherit the Wind,” and, well, “Town Without Pity.” In books, films and TV dramas of the period, faux Southerners never stop fanning themselves, shouting “Hosanna” and condemning blasphemers, carefully dropping the “g” from every verb.

Whether this is self-righteous Yankee stereotyping or a logical backlash against Southern intolerance and McCarthy-era witch hunts ain’t fittin’ talk for an opera review. Suffice it to say that the peanut-brained, walnut-souled townspeople in “Susannah” made other fictional Southern-gothic cities look as hip as Amsterdam.

Susannah’s only defender is her stalwart but soused brother, Sam, sung with a big voice and a big heart by Matthew Eldred.

As Susannah, Toy had to maneuver in a tight crevice of despair and frustration all night, but she somehow managed to show some earthy nut through her Jordan-almond shell of virginity. She stretched out fetchingly in two “Over the Rainbow”-type arias, expressing her yearning for a better life.

As The Rev. Blitch, Brad Walker dropped a huge, heavy voice, like the boulder being rolled away from the tomb of Jesus. Fusing his acting and singing skills into a knot of spellbinding neuroses, Walker stole the second half of the show, in part because the Reverend is the only character who truly changes in the play. (Susannah just goes crazy, and that’s not the same.) When he agonizes over his rape guilt and begs the town to take Susannah back, he basks in a full measure of audience sympathy denied to one-note victim Susannah.

The rest of the cast acquitted itself quite well, with a memorable turn by Dale Powell, as Susannah’s timid suitor, Little Bat. It falls to Little Bat to inform Susannah that her brother, Sam, has killed Blitch while he was baptizing townspeople in the river. When Powell sang “pool of blood” in his quavering, queasy voice, you could almost see the ichor spreading in the water.

Down in the pit, the MSU Orchestra and director Rafael Jimenez built an elegiac mountain range under this Tennessee tragedy. Floyd’s music has a dissonant, tortured beauty perfectly suited to the opera’s philosophy: America is a beautiful country with starry nights and green mountains, so why do we turn it into a living hell? (To further this idea, Jeremy Hunt’s sets were exactly as stark and scary as they needed to be.). The various and subtle cross-currents of menace and beauty from the pit helped elevate the opera’s scenario from a cruel cartoon to a rich oil painting. Near-perfect synch between singers and orchestra didn’t hurt. The performance often integrated to the point where none of the parts stuck out at all. When Walker’s deep-voiced reverend sang a duet with a growling contrabassoon, they sounded as tight as two twisting pit vipers. Victims can be a bore, but predators never cease to fascinate.