PROVIDENCE — She’s a little bit country; um, she’s a little bit rock ’n’ roll too.

Carrie Underwood brought to the Dunkin’ Donuts Center last night the kind of rock-influenced country that gets you on the charts in the post-Gretchen Wilson era and the kind of Diane Warren-influenced power-ballad pop that got her to the winner’s circle on American Idol. And while the mix was sometimes uncomfortable, the powerful Underwood voice blended it — perhaps not seamlessly, but smoothly.

The opening sequence, with “Flat on the Floor,” a mid-tempo, guitar-heavy Wilson-esque rocker; the follow-up “Wasted,” a lush mid-tempo pop tune that, but for the pedal steel guitar, could’ve been sung by Cher; and the Martina McBride-style “Get Out of This Town,” a loping ode to the open road, set the template. This didn’t leave a lot of room for a lot of originality, but plenty for versatility, and Underwood’s voice — strong and able to nail the high, hard ones without sounding brittle — filled all bills.

Mixing songs from her two albums, 2005’s Some Hearts and last year’s Carnival Ride, Underwood straddled these lines for the rest of the 90-minute show. While the first album was more of a post-Idol cash-in, with familiar pop sounds, Carnival Ride was more of a contemporary country move, and while it yielded the cloyingly apple-cheeked “All-American Girl” it also contained last night’s highlight, “I Told You So,” a Randy Travis countrypolitan ballad that Underwood nailed.

Any Idol winner, or even contestant, has a few obligatory autobiographical songs in their set, and Underwood was no exception last night, with the sequence of “I Ain’t in Checotah Anymore” and “Crazy Dreams,” but in general the show was not a major topic of conversation, and the “Oh my God, I can’t believe I’m here”/“Oh my God, it’s really her” performer-audience dynamic that dogs many Idol contestants’ shows was surprisingly light.

The contemporary country singer is almost expected to have a classic-rock tune in his or her repertoire, and the first encore, which mixed the Guns ’N Roses songs “November Rain” and “Paradise City,” was Underwood’s contribution. Her band’s up-tempo pounding was exhilarating after the mostly mannered regular set (particularly the closer “Twisted”), and Underwood’s voice roughed up nicely.

It’s good to be versatile, but the next step for Underwood is to develop a consistent persona. The ability to combine songs such as the Hallmark-ready “Jesus, Take the Wheel” and the revenge rocker “Before He Cheats” in one set could, in some hands, be eclectic; last night, it felt all over the map. Like so many Idol success stories, she can sing whatever she wants, but last night it felt like it was time for her to make some decisions.

Opening act Josh Turner, a victim of the flu, canceled at the last moment.

rmassimo@projo.com