ANTICIPATION AND MEMORY: The flirtatious maid (Katrina Michaels, on left), the middle-aged lawyer Fredrik (Evan Thompson), and Fredrik’s very young wife Anne (Miyuki Miyagi) anticipate, with wildly disparate fears and desires, a romantic “Weekend in the Country” in the first act finale to Princeton Summer Theater’s production of Stephen Sondheim and Hugh Wheeler’s musical comedy, “A Little Night Music,” playing through July 1 at the Hamilton Murray Theater on the Princeton University campus.

Stephen Sondheim acknowledged some conflict in his collaboration with the director Harold Prince on the original 1973 production of A Little Night Music: “Hal had described the show as being ‘whipped cream with knives,’ but he was more interested in the whipped cream and I was more interested in the knives.”

A Little Night Music, music and lyrics by Mr. Sondheim and book by Hugh Wheeler, is more than replete with both “whipped cream” and “knives,” and Princeton Summer Theater’s current production, playing for just one more weekend at the Hamilton Murray Theater on the Princeton University campus, delivers both the light and the dark, farce and tragedy, with unerring balance, taste, and sophistication.

Set in Sweden at the start of the twentieth century and based on Ingmar Bergman’s film Smiles of a Summer Night, Night Music ran for 601 performances in its original Broadway production, starring Glynis Johns, Len Cariou, and Hermione Gingold, became a movie in 1978 with Elizabeth Taylor, Mr. Cariou, and Ms. Gingold, then was successfully revived for 425 performances on Broadway three years ago with Catherine Zeta-Jones, later replaced by Bernadette Peters, and Angela Lansbury, later replaced by Elaine Stritch. It is, along with A Funny Thing Happened on the Way to the Forum (1962), Sweeney Todd (1979) and Into the Woods (1986), one of Mr. Sondheim’s most popular musicals, but in its depth, complexity of music, plot, theme, and subtle shifts of tone, it does pose formidable challenges for performers and audiences.

This youthful and ambitious Princeton Summer Theater Company — with seasoned professional director Adam Immerwahr at the helm, a dynamic and experienced cast of undergraduates, and recent college graduates from Princeton University and elsewhere, a first-rate, professionally-led design and technical crew, and a talented pit orchestra of nine — is up to the challenges and delivers a lucid, richly nuanced, thoroughly entertaining performance.

A Little Night Music is all about love, with themes and variations; perspectives from youth, middle age and old age; love eagerly anticipated, love fulfilled, and love remembered.

Three is the magic number here, as the show progresses in threes. The music is mostly in triple time — a sort of waltz musical — and the plot follows a series of no fewer than six shifting triangles of desire and romance. The music is complex. More typical of operetta than Broadway musical A Little Night Music, created in the style of late nineteenth century Viennese operettas, has been revived twice by the New York City Opera, in addition to its multiple productions in various venues throughout the world.

A Little Night Music is a tantalizing mix of bedroom farce and psychological tragedy, of bright romantic comedy and bitter reflection on the realities of male-female relationships, of true love and wistful regret, of human folly, and the wisdom of age and experience.

When Desiree (the luminous Sarah Anne Sillers), after a show-stopping rendition of “Send in the Clowns,” asks her middle-aged lover Fredrik (Evan Thompson), “Was that a farce?” and he replies “My fault I fear,” they seem to be referring to their problematic relationship. But she could just as well be asking about the whole show and its views of the human comedy of love and life.

The plot focuses on the story of Desiree, a touring actress, and her meeting after many years with her old flame Fredrik, who, intent on “renewing his unrenewable youth,” has recently married the lovely 18-year-old Anne (Miyuki Miyagi), who (somewhat implausibly) remains a virgin eleven months after their wedding.

The attraction between Fredrik and Desiree is rekindled. In their cleverly ironic duet “You Must Meet My Wife,” the two ex-lovers move quickly from uneasy propriety into a renewed romantic entanglement. But Desiree’s married current lover, the blustery, belligerent Count Carl-Magnus (Andrew Massey), is furious and seeks revenge on Fredrik.

Mr. Massey is not a singer, but renders the comical Carl-Magnus with convincing poise and swagger, as he talks and sings his way through his sexist “In Praise of Women” in act one, then clashes directly with Mr. Thompson’s Fredrik in act two for a cleverly choreographed, deftly timed, humorous confrontation in “It Would Have Been Wonderful.”

The two deceived wives, Carl-Magnus’s determinedly outspoken Charlotte (Maeve Brady), and Fredrik’s wife Anne, renew an old acquaintance and plot together to confound Desiree and end their husbands’ adulterous affairs. Their memorable duet “Every Day a Little Death,” offers an unsurprisingly cynical assessment of their husbands, their marriages and the state of love — “Men are stupid, men are vain,/Love’s disgusting, love’s insane,/A humiliating business!”

The plotting and the triangular liaisons multiply further as Fredrik’s impulsive nineteen-year-old son Henrik (Mark Watter), a scholarly seminary student and cello player, after a sexual dalliance with Petra (Katrina Michaels) the maid, finds himself desperately in love with his stepmother. Petra moves on to more satisfying fulfillment for her erotic passions in the form of the butler Frid (Patrick Morton). Ms. Michaels’ Petra expresses her colorful, forthright character and lusty outlook on life in a rousing solo, “The Miller’s Son.”

From beginning to end, Desiree’s daughter Fredrika (Emma Watt) and Desiree’s mother Madame Armfeldt (Carolyn Vasko), one too young and the other too old to be involved directly in the erotic dances of desire playing out on the stage before them, observe and comment on the proceedings. Ms. Vasko makes a sixty-year stretch in age to portray the elderly matron in her wheelchair, a sharp-tongued, commanding figure of strength and wisdom in the role made famous first by Ms. Gingold, then Ms. Lansbury and Ms. Stritch. Ms. Watt’s Fredrika is also memorable and consistently convincing as the inquisitive young granddaughter. Their relationship is intriguing and moving to witness.

In Ms. Vasko’s solo number, “Liaisons,” she may miss a few notes of the melody, but she forcefully delivers the meaning of the lyrics and the essence of character, as Madame Armfeldt nostalgically reminisces about her colorful past and laments over the declining standards in the art of love: “Where’s discretion of the heart, where’s passion in the art, where’s craft?”

Also providing perspective throughout the show is a quintet of waltzing singers, lovers — Mr. Lindquist, Mrs. Nordstrom, Mrs. Anderssen, Mr. Erlanson, Mrs. Segstrom (Sam Eggers, Abigail Sparrow, Emily Verla, Brian Hart, Jessica Anne Cox respectively) — who, as Mr. Immerwahr writes in his program note, “haunt the space, each with their own variations on the themes of the musical.” Like a late romantic Viennese version of an ancient Greek chorus, this polished ensemble observes, enhances the rapid transitions between scenes, and helps to establish the background and tone of the show.

The sturdy, functional set design by Jeffrey Van Velsor, with its Scandinavian elegance and simplicity, and complex, nuanced lighting by Alex Mannix serves this show admirably. Necessary furniture — bed, tables, chairs, desk — is wheeled on and off efficiently as the scene shifts from one residence to another and eventually to the Armfeldt country estate gardens, terrace, dining room, hallway, and bedroom. Three steps upstage lead to a wall of windows and French doors, behind which is the orchestra pit, lit in varying colors and degrees of clarity to suit the mood of the scene — all in all a striking visual effect. The close quarters and intimacy of the Hamilton Murray Theater lend themselves admirably to the delicacy and human scale of the drawing-room comedy enacted here.

Ben Schaffer brings an experienced, professional hand to the challenges of sound design and technical direction. Music director Kevin Laskey, another local professional and recent Princeton university graduate, leads the excellent nine-piece pit orchestra with poise and precision through the tangled and demanding Sondheim score.

Pulling this major production together, Mr. Immerwahr has cast the show with unerring intelligence and directed with distinction. The pace moves rapidly from start to finish. Every moment seems carefully, precisely rehearsed; with scenes shifting smoothly; diction, projection, and balance between actors and orchestra, between comic and serious, making all the witty shades of meaning and complex dialogue clear and accessible.

Costume designers Julia Bumke and Ariel Sibert have assembled a rich array of formal wear befitting the individual characters and helping to create the appropriate world of the Swedish upper class in 1900.

Madame Armfeldt promises her granddaughter at the start of the play that “the summer night smiles. Three times … at the follies of human beings, of course. The first smile smiles at the young, who know nothing. The second at the fools who know too little, like Desiree. And the third at the old who know too much — like me.” A Little Night Music, in this dazzling Princeton Summer Theater production, transcends the time and place in which it is set, transcends its farcical plot, transcends the difficulties of Mr. Sondheim’s sometimes cerebral music, and it transcends the discord of these characters’ lives. It delivers a striking commentary on the human condition, the frailty of love and life. Mr. Immerwahr and his richly talented company offer an exciting opening to PST’s diverse summer season. Don’t miss it.