NORTHBRIDGE — Early in Willy Russell's “Educating Rita,” Rita asks Frank what the meaning of “assonance” is. He explains it's the use of similar vowel sounds, notably as an alternative to rhyme in verse, and gives her an example.

After a moment's confused contemplation, Rita's face lights up with the retort, “Oh, it's getting the rhyme wrong!”

That may be one way of defining “assonance,” as Frank amusedly agrees, but what Pilgrim Soul Productions' captivating “Educating Rita” does is get it triumphantly right. It's an exhilarating example of what community theater can do at the highest level, one that rivals professional theater in every conceivable way. Not only that, but the performances of Aimee Kewley and Matthew J. Carr on Friday evening could stand beside those of Oscar-nominated Julie Walters and Michael Caine in the 1983 film.

Russell's charming variation of “Pygmalion” is about Susan White (Kewley), a 26-year-old hairdresser who hungers to better herself. She enrolls in an open university course in English literature, taught by Dr. Frank Bryant (Carr). Frank is a middle-aged, disillusioned alcoholic who hides his liquor bottles behind books in his office and has taken on the after-hours tutorial to subsidize his drinking. What a pair these two make.

It isn't long before Susan, who prefers to be called Rita, is vilifying E.M Forster's “Howard's End” for “not caring about the poor.” Kewley's rapacious, emotionally translucent portrayal of Rita is something to behold, as she challenges Frank's hallowed opinion of Forster, infatuating him with her uninhibited view of the world and upending his stagnant academic precepts. The minute she enters his office, she sniffs around the bookshelves, examining Frank's artifacts with voracious curiosity, inhaling this alien environment with inspired physical restlessness and commenting with an authentic Cockney accent. She's a catalyst all right, yanking Frank out of his stupor and giving him a new sense of purpose.

Kewley's range is stunning. She gives every word of dialogue its proper weight and rhythm, whether she's being jocular with Frank or painfully revealing her insecurities and stifling family life.

Carr plays wonderfully against Kewley's gravitational force, etching Frank with a thoughtful amalgam of cynicism, weariness, self-loathing and bemused affection. He imagines second chances in life with this enervating creature, and it rankles him to see her become the very thing he detests — a pretentious academic snob who can quote the poetry of William Blake with affected nonchalance. He criticizes her for becoming what she's not.

Carr and Kewley are intuitively in sync with the ebb and flow of the play, fluidly embracing its lighter and more serious moments. Kewley movingly reveals Rita's anxiety at walking away from an invitation to Frank's dinner party — after looking in at his friends through his living room window — because she considers herself a freak, an outcast to Frank's elevated social circle. Later, as Rita gains intellectual confidence with her own self-absorbed, superficial group, Frank can't bear the thought that Rita thinks his long-ago attempts at poetry are brilliant. Up to now, their relationship has been mostly one of an active (Rita) and reactive (Frank) nature, but Carr dramatically underlines Frank's simmering self-disgust here by angrily ripping his dormant manuscript to shreds and accusing Rita of a total lack of comprehension.

What “Educating Rita” finally does teach our endearing duo is that education extends beyond literature. Neal Martel is quickly becoming an actor's director par excellence. He and Alan Standrowicz have also provided Frank with an impressively designed, hermetically sealed office set. As Rita would say, it's brilliant.