Indian Summer Jars is like any other relationship, but with singing.

"Our strengths and our weaknesses balance each other," says Sarah Beth Deardorff, who makes up one half of the band's core. "It's easy and it's not. It's like any working relationship."

Singing partner Sarah King -- and yes, they briefly considered and quickly discarded band names such as Sarah Squared and The Two Sarahs -- says they met at an open-mic night at Appalachian Brewing Co. in Harrisburg.

"It wasn't like a 'love at first sight' kind of deal," she says. "We got to know each other first."

They moved in similar circles, King says. They ran into each other at shows, and they eventually decided to work together. One rehearsal together was all it took to seal the deal. "I thought she was incredibly talented, but she needed to get out some better venues," King recalls. "But she was only 19, so we kind of had to sneak her into the bar scene."

Deardorff was working solo at the time, so when King's other musical partnership disbanded, a team-up seemed obvious -- even if it did take a little while to iron out the kinks.

"Sarah had more experience working with bands than I did," Deardorff says.

"It took a while. I wasn't used to working with someone," she adds. "There's so much work involved. But spending as much time together as we have, we've learned how to complement each other. And Sarah is such a good listener, she follows my lead."

"Sarah Beth marches to the beat of her own drum, rhythmically, but once you get used to it, you can figure out where it's going to head," King interjects. "Besides, I'm a middle child, so I'm a little more used to mediating. Maybe it's because I'm a Scorpio. Also, I'm a little older than Sarah Beth. We both bring different experiences to the band."

The name, Indian Summer Jars, was likewise a collaborative effort.

"Sarah Beth came up with the name, and I came up with the meaning behind the name," King says. "It's about that time in Indian summer when the weather changes. It's warm, and people are more likely to be spontaneous ... venturing outside of their comfort zone, breaking from routine and doing things they might not ordinarily do. It's a time to live life a little more to the fullest. The 'jar' part of the name is about preserving those moments ... and sharing them with others."

That's kind of what she was thinking when she coined the name, Deardorff says, but, "well, if you would ask me about it, it would take me a half an hour to get it out. I had all those things in mind, but sometimes it can take me longer to explain something."

King laughs.

As a duo, the two Sarahs are a sum greater than its parts. Their folk- inflected sound is defined by layered vocal harmonies and strong guitar lines -- a sound reminiscent of the Indigo Girls and the Nields -- accented by percussion provided by periodic third member, Kelly McClain.

Deardorff does the heavy lifting when it comes to composition, both Sarahs say. Then they work together to polish the work in progress to its final form.

Deardorff says writing is an uncertain process.

"I wish it was easy for me as sitting down and saying I want to write something, and writing it. It's pretty unpredictable," she says. "Morning is a big creative time for me. And a lot of times I'm just playing and a song will come out. ... You know, it's deliberate, but it's not."

"It's definitely driven by your moods and your emotions," King tells her. "You're sensitive to your environment, which helps you with your writing."

"Usually I'll finish the song. Then I'll bring it to Sarah," Deardorff concludes. "Sarah and Kelly will help me work out the kinks, or the parts that are shaky. It takes different ears to hear it."

A working partnership since 2006, Indian Summer Jars has produced two CDs -- Similar in 2008 and Catalyst in 2011 -- and more than 250 original songs. "We really listen to each other," Deardorff says. "We're two separate vocalists. You might call me the lead singer, but our vocal parts are totally equal. And we have the same kind of energy, which is really cool."

"It's kind of like any relationship," King adds. "It comes down to communication. We have to give each other breaks sometimes." ("Yep!" Deardorff exclaims in the background.)

"And just like in any relationship that lasts, you have to be willing to compromise and work at it, mutually," King says, firmly.

Both Sarahs have full-time jobs outside of their musical life together, but performing never feels like work, both insist.

"If one of us is in a mood, the other one of us brings us out of it," King says. "Then you start playing, and it all just melts away ... It always does feel good."

Visit the Indian Summer Jars website for more information on the band, including performance dates.