Sutton Foster sang plaintive and comic tunes on Saturday. (Laura Marie Duncan/Courtesy of George Mason University Center for the Arts)

Sutton Foster, Broadway’s busy leading lady turned hopeful TV star (ABC Family’s “Bunheads”), chose to glow softly rather than to beam white-hot Saturday night at George Mason University’s Concert Hall. Of course, the irresistible Foster, in a teal cocktail dress and with her dark hair cascading over her shoulders, delivered rousing showstoppers; the encores came from her Tony-winning turns in “Thoroughly Modern Millie” and last year’s “Anything Goes.” But, for the most part, her 75-minute performance was less about big finishes than finely crafted small ones.

Singing to arrangements by musical director and pianist Michael Rafter, Foster seemed more reflective than in her appearance last year at the Kennedy Center. Some of that older material is still in the act: John Denver’s “Sunshine on My Shoulders,” sung plaintively and now introduced as an ode to Foster’s new home in Los Angeles; Duke Ellington’s majestic, hopeful “I Like the Sunrise”; and “Air Conditioning,” a joke tune about the one thing a man simply has to have, rendered with quick, light comic timing and Foster’s effortlessly droll lyrical inflection.

The tone Saturday night, though, was more consistently calm, even questioning. “How Little We Know,” sung lightly, was a fitting pre-encore ending that Foster and Rafter built by fusing Stephen Sondheim’s wistful “Anyone Can Whistle” with “Being Alive,” the climactic “Company” number that has become a cabaret warhorse. Foster freshened “Being Alive” with a deeply ruminative approach, lingering prayerfully on the phrase, “Vary my days.” Then Foster drove the song to its emotional crescendo with her reliable sterling belt, quickly and efficiently.

Surprise guests included Foster’s dog (“The man in my life,” Foster deadpanned) and Megan McGinnis, who, as she did on Foster’s 2009 CD “Wish,” harmonized with Foster on Craig Carnelia’s dramatic, haunting “Flight.” But the most lasting impression came from the collective effect of burrowing into such tunes as “Nice ‘n’ Easy,” “The Nearness of You” and “Warm All Over.” Foster was more sweet than torchy but consistently supple and elegant, and quietly dramatic; it was the kind of grown-up singing that makes you lean in, wanting to get as close as she is to the song.