CAMBRIDGE — For anyone who was paying attention during her six seasons on “Saturday Night Live,” it was clear that Ana Gasteyer could really sing. Certainly, there are quite a few “SNL” alums who could pull off comic singing, as she herself did as exaggeratedly operatic music teacher Bobbie Mohan-Culp. But there were also plenty of times when a legitimate voice poked through and made itself known. So when the “six-time ‘New York Times’ crossword clue” (per her introduction) came to Sanders Theatre Saturday night for a concert of cabaret-style songs, it wasn’t a surprise to hear her show off some genuine vocal chops.
What was perhaps unexpected was just how delicately Gasteyer threaded the needle. A few songs had comedic angles, but she was never so taken by that fact that she tipped over from being a singer to simply portraying one. The kookiness of the hot jazz of “Crazy People” and “I Wish I Could Shimmy Like My Sister Kate” was baked into the style, so singing them straight was enough. Her spirited romp through “One Mint Julep” similarly captured the comic regret of its lyric, and while she updated “I’m Hip” with references to modern tech and social media, it likely didn’t play much differently from when Blossom Dearie sang it in the bebop era.
But soon came the Magnetic Fields’ “The Book of Love,” a gentle breath of a song with punch-line-spiked verses giving way to achingly sincere choruses. It set the tone for a terrific rendition of Carrie Underwood’s “Before He Cheats” in the style of Peggy Lee’s “Fever,” Gasteyer building to a powerful belt on the bridge before dropping to almost nothing and hanging there powerfully. She was affecting and heartfelt on “(Theme From) Valley of the Dolls” and a “Defying Gravity” that traded its typical bombast for a startlingly effective vulnerability.
In a way, she did the same in her many extended between-song digressions (including riffs on her obsession with Barbra Streisand’s coffee-table book “My Passion for Design” and a harrowing drive through an Iowa blizzard involving two Luke Johnsons), which had the punch of an experienced comedian telling funny stories that weren’t rehearsed routines. Gasteyer didn’t lean on comedy as a crutch, either in her banter or her songs. Even when she was working with humorous material, she never once came across like she didn’t take it seriously.
Presented by Celebrity Series of Boston. At Sanders Theatre, SaturdayMarc Hirsh can be reached at email@example.com.