"I'm a debutante -- at 45!" Susan Cowsill exclaimed to the audience at Iota on Monday night. Then Cowsill launched into the countryish title cut from her recent debut solo album, "Just Believe It."

The little girl who starred with her '60s family band the Cowsills has grown into an adult with star quality -- and another musical family, a band that is also called Susan Cowsill.

Drummer Russ Broussard, Cowsill's husband and former bandmate in the Continental Drifters, guitarist Chris Knotts and bassist Rob Savoy provided bold sonic backing for Cowsill's slightly husky, engagingly emotive voice. Knotts and Savoy got several lead-vocal turns, including Savoy's powerful Cajun/garage-band number "Avec Moi."

But Cowsill, who combines a slightly goofy persona with a deeply assured musical presence, earned her title as bandleader/band name with a varied selection of songs. Her wistful yet robust reading of Sandy Denny's "Who Knows Where the Time Goes" set the more familiar Judy Collins version adrift in the breeze. The more delicate of her own compositions, including "Peaceful Waking," built into sophisticated power ballads.

Ultimately she proved herself a rocker at heart, with the Continental Drifters' ebullient "Rain Song" and "Someday," a biting indictment of an ex-lover called "Talkin' " and "I Know You Know" -- for which she strapped on, and seemed a bit daunted by, an electric guitar.

"I'm kinda new at this," she confessed. But as she has done for nearly 40 years, she made it work just fine.

-- Pamela Murray Winters