SNL alum Ana Gasteyer in concert at Sanders Theatre

This past Sunday, former “Saturday Night Live” cast member Ana Gasteyer returned to her ensemble roots in FOX-TV’s live presentation of the musical “Grease.” She joined Julianne Hough (Sandy), Aaron Tveit (Danny), and Vanessa Hudgens (Rizzo) as Rydell High School’s Principal McGee, which was originally played by Eve Arden in the 1978 film.

The multi-talented actress and comedian trained early on in her career with the LA improv and sketch comedy group, The Groundlings, after having found her calling and “her people” at Chicago’s Northwestern University. Although she first went to Northwestern as a vocalist, she “very quickly got sucked down the comedy rabbit hole,” recalls Gasteyer by phone from her home in Los Angeles.

Her training at The Groundlings laid the foundation for her career in comedy and also prepared her for her big break in 1996 — joining NBC’s “Saturday Night Live.” Of her time with the famed Los Angeles troupe, the actress really learned that she loved being part of a group.

“I’m an ensemble performer,” she said. “I love collaboration. I love working with other people. I love writing with other people. I submitted to those inclinations at The Groundlings for sure.”

During her time there, Gasteyer says it was much more than “just having fun and taking improv classes. … The training is very consistent there and everybody has to matriculate, so it’s not like you just show up and take classes. You have to move through those levels together.” While at The Groundlings, she worked with future SNL cast mates Maya Rudolph, Will Ferrell and Chris Parnell.

After a six-year run on SNL, where she was known for the characters — high school music teacher Bobbie Mohan-Culp, National Public Radio “Delicious Dish” host Margaret Jo McCullen and her dead-on impression of Céline Dion — the classically-trained vocalist had a renewed interest in musical theater.

For the first five years after leaving the series, she performed in a number of musicals and concerts, including originating the role of Elphaba in the Chicago production of the musical “Wicked” in 2005, for which she was nominated for a Jefferson Award for her performance.

With a slate of projects in the works including the TBS comedy “The Group” and a recurring role opposite comedian Maria Bamford in the Netflix comedy “Lady Dynamite,” the vocalist once again is ready to take center stage when she performs in concert at Sanders Theatre on Saturday as part of the Celebrity Series of Boston. Her upcoming performance is described as “evoking the swagger of an era when a lady ruled a nightclub and an audience knew they were in for a good time.”

Gasteyer brings a sense of humor and a bit of sassiness to her performance of the 1950’s classic songs “One Mint Julep” and “Proper Cup of Coffee.” “Serious singing is just not my thang,” says the vocalist.

Of the concert she describes, “ultimately, I returned to what I actually listened to and what I actually had fun singing. Those kind of entertainer’s era, the ‘jazz wink’ that we include in the show just kind of marries both of those things I do the most, which is kind of a light-hearted approach, a fun patter–focused show that also features great music,” says Gasteyer. “There’s room for improvisation both musically and comedically.”