Chalk it up to busyness, drunkenness or simply forgetfulness — it’s hard to pin down the Massachusetts-bred Unearth.

After waiting a full hour past the designated interview time and counting how many tiles are actually on the ceiling, you begin to agree with your first assessment. A half-hour later, the phone finally rings.

Unearth is a hard band to get a hold of.

It should be. After touring last year on the MTV2 “Headbanger’s Ball” Tour, the band is once again in the lineup for the much-hyped tour, not to mention this summer’s main event for rockers, Ozzfest.

“Everyone’s having a good time,” says Unearth guitarist Ken Susi from the band’s latest stop, Detroit. “The crowds have been pretty responsive.”

Unearth, along with Hatebreed, Damageplan and Drowning Pool, has been criss-crossing the country, bringing its music to the masses, and in the process, trying to start a revolution, Susi says.

“It’s time a more aggressive style comes to play,” he says, referring to the “trendy” music scene as of late.

So how does Unearth, which has been around since 1998, see the musical climate?

“It’s OK, but certain bands get to stick it out and remain, and I think that we’re one of those,” Susi says.

As for the band’s philosophy, Susi says it boils down to one thing.

“At the end of the day, we all have to look each other in the face and ask if we’re happy about what we’re doing,” Susi says.

And what has made them happy lately, Susi says, is touring, be it in their home state on the East Coast, or the Val Air Ballroom, 301 Ashworth Road, Des Moines, which is where the “Headbanger’s Ball” lineup is heading next.

As for the differences in geography, Susi says it really doesn’t matter to him where they play.

“Without the East Coast, the West Coast wouldn’t exist, and vice-versa,” he says. “I love the Midwest for one reason — kids come out and take both sides of the action.”

Susi says the whole band, which is made up of Susi, vocalist Trevor Phipps, guitarist Buzz McGrath, bassist John Maggard and drummer Mike Justian, is excited to be playing Des Moines.

“Really, there’s not a lot to do [in Iowa],” Susi says, “so the kids are absolutely itching for shows.”

The tour isn’t one big party though, as the band is ultimately there to support its new forthcoming album, titled “The Oncoming Storm.”

“It’s one of the best records to date,” Susi says. “There’s a lot of intensity and diversity throughout the album. We wanted to write an album where the moment you put it in, you know it’s Unearth.”

Getting the band’s name out there is one of the reasons the band decided to do Ozzfest this year.

“It’s gonna be a great learning experience,” Susi says, although he does admit that not all of the tour will be educational.

“There’s probably going to be a lot of mischief going down,” he says, laughing.

Getting serious, Susi finally gets to the crux of the Unearth mission. With his goals in mind, it wouldn’t be surprising if Unearth becomes an even harder band to get a hold of.

“We’re going to try to bring the underground to the forefront,” Susi says.

Who: Hatebreed, Damageplan, Drowning Pool, Unearth

Where: Val Air Ballroom, 301 Ashworth Road, Des Moines

When: 7:30 p.m. Wednesday

Cost: $28.75