Much like love itself, A Time for Love has a way of sneaking up on you.

Presented by the Rubicon Theatre Company through Feb. 25, the world premiere show takes a magnifying glass to the ever-changing nature of the emotion that makes the world go round. Beginning with the dawning of lust and the shattered expectations of life after marriage, the show, like one of its songs, is “Not What I Expected.”

Conceived as a musical valentine, with music and lyrics by Tony Award winner Richard Maltby Jr. and Oscar and Grammy Award winner David Shire, the show features tunes from the pair’s collaborative musicals, including Starting Here, Starting Now, BABY, Closer than Ever and Big, as well as songs original to A Time fro Love.

After the lights went down and the first song began, I was struck by just a touch of fear that the piece may have been designed primarily for the John Tesh crowd (not that there’s anything wrong with that). But a few tunes in, I realized that the show was essentially about the unexpected, and about how those first golden moments of being lovestruck are ultimately changed by the realities of daily life.

The 70-minute show, which is all song and zero dialogue, is impressively backed by live music that assists the actors in breathing truthful, layered complexity into the performances. Alternately funny and heartbreaking (and sometimes both, simultaneously) the songs capture the many shades of relationships as they begin, develop and morph into something else altogether.

The exquisite Lois Robbins plays “The Woman” in the show, and she exudes the spirit of a woman in love. As the love story between “The Woman” and “The Man” (portrayed by the superb Brian Sutherland) begins, we watch as their feelings and roles change and as they become overwhelmed by the details of living and by each other, before being ultimately torn apart and haunted by regret.

What at first seemed like a glossy, generic duo becomes a pair of real people — people we all know, people who are so like us. Sutherland is positively heartbreaking as a man who wishes he had done things differently. He sheds real tears as he sings, and his performance, along with his perfect voice, are guaranteed to leave a sizeable lump in your throat. His performance of “One of the Good Guys,” about resisting the urge to be unfaithful, was an unexpected, interesting twist in the couple’s saga.

Likewise, Robbins, with a lovely set of pipes of her own, is a woman we can relate to. Her performance of “Stop, Time,” about a woman’s love for her children, is sweetly moving.

Together, the stressed-out duo fabulously enacts the demands of daily life, and makes a hilarious pair.

Video footage of real couples relating stories about their relationships are inserted throughout the show. These couples, who are touching, genuine and hilarious, serve as fitting reminders that love takes many shapes.

By the show’s close, it was clear that the performance isn’t about the romance and frills of couplehood. It’s about the necessity of knowing that, no matter how crazy life becomes, it’s always time for love.