Pistol Annies' 2013 album, Annie Up. Photo courtesy of Sony Music Nashville.

At first, the Pistol Annies seemed almost too good to be true. Here was a one-of-a-kind band begun out of the blue by one-of-a-kind singers and songwriters Miranda Lambert, the proven chart-topper of the group, and Angaleena Presley and Ashley Monroe, who’d accumulated their share of credits in Nashville, a band whose 2011 debut album Hell on Heels was a fantastically feisty breath of fresh air for country music.

Two years on, it’s clear the Annies are not only very real, but very here to stay. Their days of collaborating under the radar without any expectations are gone, though. So they knew exactly what they wanted to do on their second album—up the ante, or in their words, Annie Up.

The title’s no bluff. Instead of smoothing the edges, slathering on the slickness or playing it the tiniest bit safe, the Annies have returned with an even bolder song cycle than the first. And the way sparks fly when these three put their heads together, it’s no wonder the Smoky Mountain cabin they holed up in to plan the new album later burned in a wildfire.

Wildfire is also an apt metaphor for how the Annies’ music caught on. They were an unknown quantity when they stepped up to the microphones during the Academy of Country Music’s April 2011 television special Girls’ Night Out, but they finished that year with an album that debuted at No. 1 first on the iTunes all-genre chart, then on the Billboard country chart—an especially impressive feat considering Hell on Heels was initially only available for download—and that won over country, rock, roots and pop critics alike. Besides topping The Nashville Scene’s Country Critics Poll, it was, for example, one of only three country albums to make Rolling Stone’s list, Lambert’s Four the Record being another.

Fans quickly embraced Hippie Annie (East Tennessee-born Monroe), Holler Annie (Kentucky-born Presley) and Lone Star Annie (Texas-born Lambert) as a trio of modern hillbilly heroines, identifying with them as women who’d be a hell of a lot of fun to hang out with and hanging on every unvarnished word they sang. It didn’t take long for the Annies to graduate from performing a few songs in the middle of Lambert’s set to drawing crowds in their own right.

Recalls Lambert, "We did our first headlining show, and we didn’t know if people would know us from Adam. We didn’t have a single. We got out there, and people sang every damn word to every song. We were shocked. I mean, completely shocked."

Not even the sharpest minds in the music business could manufacture a group with that kind of instant impact. The Annies’ origin story drives home the fact that there was nothing the least bit prefab about them. Here’s how it went down in a nutshell: during a songwriting and reality T.V.-watching slumber party at Lambert’s place, Monroe couldn’t shake the feeling that she needed to call up Presley—another co-writer and gal pal—and get her to email her songs over for Lambert to hear. It didn’t matter that it was 2 a.m.

"Looking back at that, that was absurd," Monroe admits with a laugh.

Lambert agrees, "Like, who does that?"