There have been some big changes for hometown heroines the Pack a.d. over the past few years, and not just the kind that make it difficult to connect the band’s new Do Not Engage to its early primal-blues-based releases.

Reached at a tour stop in Austin, Texas, singer-guitarist Becky Black confesses that keeping perspective on where the two-piece has been, and where it’s going, isn’t easy. Along with drummer Maya Miller—who also takes part in the interview—Black has been busy enough that everything seems like a blur.

“The years sort of blend together for me,” the Pack a.d.’s frontwoman says. “I’ll always be, ‘That just happened’ and then someone else will be, ‘No, that was three years ago.’ Overall, though, things have been, um, interesting. I’m a little surprised—well, maybe not surprised, but more think that it’s kind of cool that we’ve gotten this far. A lot of people don’t.”

Black is talking about more than making it to album number five. Starting with 2010’s We Kill Computers, the Pack a.d. has successfully reinvented itself, the band having ditched the grimy Mississippi Delta blueprint that shaped its first two records, Tintype and Funeral Mixtape. Listen to the work of Black and Miller today, and you’ll hear a basic foundation of grungy protopunk, snarling pop, and greased-lightning garage rock.

This ongoing evolution has helped the group break out of the underground. With 2011’s Unpersons, the Pack a.d. cracked commercial radio, both “Sirens” and the sing-along monster “Haunt You” making a dent on playlists across the country. The duo’s infrequent hometown shows are now legitimate events taking place at respected midsize venues like the Commodore and the Rickshaw.

“With the last album, we decided to hire a radio publicist, and, just like that, she got our songs on the radio,” Black notes. “And they caught on, which was a new thing for us, for sure. We started seeing more people at our shows—even Top 40 people.”

On Do Not Engage, astute listeners will notice that the Pack a.d. continues to grow. Miller now does more than just hold down the back end, the timekeeper contributing background vocals to most of the songs, something she couldn’t have imagined doing a few years back.

“Becky totally forced me,” she says. “Seriously. It was like this had been her plan all along. She’d be like, ‘Okay, you’ll be singing with me now on this one,’ and I’d be like, ‘I can’t.’

Laughing, and briefly shifting to a voice that suggests she might be a fan of The Simpsons’ Ned Flanders, Miller continues: “It took me a long time to feel comfortable enough to actually sing, but Becky was just right there believing in me, every single day. So I started doing it to where it became compulsive. Now every song that we come up with, she’s like, ‘And now you sing this part with me.’ I let her boss me around and do whatever she says.”

A lifestyle change has helped Miller on the singing front, and also with her duties behind the drums and in her day-to-day life. Miller—who jokes that she began smoking at age one—quit a year ago, noting the reason was simply that it was time.

“I needed to be done with it—it wasn’t helping anything,” she says. “A great side effect has been, because I sing on so many songs now, that I can sing fully and I don’t lose my breath like I used to while playing a show. My God, I totally noticed that I used to gasp and wheeze at the end of some songs. Also, I can now go up stairs. But mostly it’s helping with the singing, which is kind of a big deal for me.”

One constant has been the band’s association with Detroit rawk-revival king Jim Diamond. The Dirtbombs bassist first mastered We Kill Computers, then slid into the producer’s chair for the follow-up, Unpersons. He returns in that role for Do Not Engage, helping give birth to a diverse record that’s the most far-reaching of the Pack a.d.’s career.

Where she once sounded like a charter member of the Fat Possum roster, Black plays it ethereal and dreamy on dazzlers like “Airborne” and “Rocket”. On “Creepin’ Jenny” the Pack a.d. combines the glam-stomp of Joan Jett with the Stooges at their droniest and druggiest. The amps are turned down low as Black goes smoky gothic chanteuse for “Battering Ram”, while “The Water” suggests the banging EDM of acts like Justice reinvented for the garage.

Both Miller and Black credit Diamond with helping get the guitar tones right on an album that is at times beautiful (the ghostly “The Flight”) as well as bruisingly powerful (the multilayered beast that is “Animal”).

“He’s a great guy who is a friend more than anything else, but he’s also really talented,” Black says. “It’s worked out with the three of us, where it’s almost like having a third member.”

But it’s still just the two of them in the tour van, even if things are in many ways different now. Continuing with the changes, the Pack a.d. has hooked up with well-established indie Nettwerk Records for Do Not Engage. Reflecting the band’s growing profile, Black now finds herself sponsored by ESP guitars, Miller having landed a similar deal with Paiste cymbals.

As for just how far the two musicians have come, from the way Black describes things, years of hard work have started to yield dividends, the band having watched the size of its audiences grow steadily. Asked to assess where the Pack a.d. finds itself today, Black jokes that she’s still not exactly in a position to afford to buy a Yaletown condo. Still, as noted, she and Miller are making records and touring rather than having to choose between the green (Starbucks) and the orange (Home Depot) aprons.

“The good thing is we’re not in debt,” Black says. “I think the only reason is because, when we used to tour relentlessly, we quit our day jobs so we weren’t making any money. We didn’t have apartments—we just toured all around the world, and because we were making very little money we didn’t spend very much money. We rarely got hotel rooms and food, so we didn’t go into debt. Now we’ve come out on top through our suffering.”