When the men of acoustic rock duo Jackopierce decided to part ways in 1997 it was a fairly familiar story from the music world: Successful band splits up to pursue different directions individually.

Of course, it was a second split that provided the unusual twist that brought Jack O’Neill and Cary Pierce back together.

“It was just a general malaise,” Pierce says of the band’s initial breakup. “The majority of divorces are caused by people falling out of love. It’s just not happy anymore.”

It’s a concept with which Pierce is all too familiar. In 2002, he was in the midst of a self-described tumultuous divorce. But it was within those painful circumstances, that Jackopierce’s former manager began pushing a reunion. At first, Pierce had considered it a pipe dream. Pierce was pursuing a solo career and working in production in Nashville – where he still works today with the likes of Creede Williams, Chris Tomlin and Katie Mariah. Meanwhile, O’Neill fulfilled his lifelong desire to move to New York, putting his drama degree to use working for The Bat Theater Company.

But as he rummaged through his belongings, clearing out his house in preparation to sell it, Pierce received another call about giving Jackopierce a second shot and decided to take the plunge. Soon they were spinning ideas for a reunion show with Vertical Horizon backing them up. Jackopierce was back.

“I love playing solo,” Pierce says, noting his shows at Jammin’ Java once a year. “But something more magical happens when we play together.”

Originally, the duo had soared to success through wide circulation on college campuses (a la Dave Matthews Band and The Samples), selling 400,000 albums before their breakup in 1997. But Pierce admits he was apprehensive about the turnout for their reunion.

“Part of you thinks that everyone forgot about you,” he says. “Even super groups reuniting, they’re a little afraid. What if nobody comes? Our career is based on the general public supporting us and if they don’t, our career doesn’t happen.”

His fears proved unfounded. The first show sold out and the results were similar for the remainder of the tour, with lines of eager fans running down the sidewalk outside the venues.

On the stage, things were just as good. Both Pierce and O’Neill put the past behind them and were ready to move on.

“We were up there in front of a hundred people or so and Jack came over, leaned in and just said ‘Hey man, I’m sorry’ and I said ‘I’m sorry too,'” Pierce recalls. “And that was it. That’s the dynamic. That’s been the way the magic happens for us.”

On Saturday, Jackopierce plays the Birchmere, and when they do, they’ll be celebrating their release of new album Promise of Summer. It’s the first original album from the group since Finest Hour in 1996. During the week of its release, the album reached No. 7 on the iTunes Rock chart and No. 41 for all genres, but more notable is the new dynamic through which the album was created.

“We never really wrote together that much. We did a little editing on each other, but this time around Jack was really willing to let me in and change stuff around,” Pierce says. “He had some comments on my songs, and when he said something, I listened because I know he’s not flippant about it either.”

The pristine harmonies and sunny effervescence that typified their early work is back in full force on the new album, with songs like the country-tinged “Everything I’m Not” and the bright-stringed title track inducing involuntary urges to turn the volume up.

“It’s top down music, it’s road trip music,” Pierce says, admitting he often draws from the same territory when he writes. “I’m always kind of rewriting that same story of a summertime romance.”

The ballads, well, they come from somewhere else.

“That sorrowful place, going through a painful divorce. I’ve been really able to draw on that.”

So, while one relationship fizzled for Pierce, it helped renew another one, for which Jackopierce fans are extremely grateful.

“Jack and I get along better than we ever have,” Pierce says. “We have really good respect for each other. I’ve got respect for his art and I think he’s got respect for how hard I work at this.”

• Jackopierce plays the Birchmere Saturday, Sept. 27 at 7:30 p.m. Tickets are $27.50. For more information on Jackopierce, visit www.jackopierce.com.