All by themselves, teenagers in Mahtomedi have recruited country music star Katie Armiger for a benefit performance to raise money to fight child abuse worldwide.

Never kids to miss a beat, several Mahtomedi teenagers have recruited emerging country music star Katie Armiger to sing for charity this week in downtown Minneapolis.

The self-made Hearts4Charity group has booked Armiger to raise money for the International Justice Mission and has jumped into a blitz of sales, promotion and marketing to attract 1,200 concertgoers.

"One night it came to me it would be really fun to do a summer concert," said Amanda Sexson, 17, founder of Hearts4Charity, who met Armiger two weeks ago at the Rice County Fair in Faribault, Minn. "She said she just loved our story and she loved younger kids taking the initiative and trying to make a difference. She thought it was inspiring and wanted to be part of it."

Bringing Armiger to the bright lights of Mill City Nights, a concert venue near Target Field, would present a challenge to even adults experienced in the entertainment world. That's why the deeds of Hearts4Charity are all the more dramatic, because the group of mostly Mahtomedi High School students lead themselves.

The inspiration for their effort started with a lemonade stand in 2004. Sexson was a fourth-grader, raising money for charity from her driveway. She soon became involved with an effort known as Operation Christmas Child, and when she received a letter from a girl in Zambia describing her joy over receiving a gift box, Sexson was hooked.

"Amanda is the eternal optimist. She always hopes something will happen," said Maddy Gildersleeve, 17, another member of Hearts4Charity, a registered nonprofit organization.

The Hearts4Charity team isn't a school group, but a homegrown version of what youth do well — taking initiative to help other people. They decide their own causes, raise their own money, and choose the charities that will benefit from their work.

"It's something that my friends and I grew to love," Sexson said. "It grew bigger and bigger the more we do it. It's really been my passion, so we want to continue."

Much of Hearts4Charity's outreach has gone to poverty-plagued Haiti. Sexson recently told her story in a children's book, "I Can Make a Difference," which she cowrote with her mother, Julie.

Money raised from sales has gone to children in Haiti, a country Amanda has visited and where much of her attention goes. The Hearts4Charity team members also make a product Sexson baked as a child, called "Peppermint Bark," that they package into 600 tins each year to benefit Haiti. A 5K road race in May raised money to help a local family adopt a child from Haiti.

Sexson said the group chose the International Justice Mission, a human rights agency, as the beneficiary for the Armiger concert because it fights oppression and sexual slavery and stands for justice for the poor. The Hearts4Charity kids research charities to make sure their hard-earned money goes to children, not to office overhead and manager perks.

"We are very careful because we see a lot of that lately," Sexson said. The group wants to make sure charities "line up with what we believe in."

Hearts4Charity will pay Armiger $1,500 to perform, and will pay Mill City a fee as well. To cover initial costs, the kids hurriedly arranged fundraising events such as bagging groceries and washing cars. "It was a bit of a scramble there for a while," Gildersleeve said.

Armiger, whom Gildersleeve describes as "a total sweetheart and super nice," is a 22-year-old singer who's quickly emerging into big-time country music. She is performing at WE Fest in Detroit Lakes, Minn., this weekend, with established industry heavyweights such as Keith Urban, Brad Paisley, Carrie Underwood and Kenny Rogers. Hearts4Charity appealed for help from several of the performers, but only Armiger answered them.

"She's actually really good," said Gildersleeve, the group's outreach leader. "She is big and her music is really good. We're really excited to hear her."

By the middle of last week, Hearts4Charity had sold 180 tickets for the concert but the kids were working hard to spread the word.

"As a high schooler, I don't know how to do this," Gildersleeve said. "I spend most of my time worrying about getting my homework in. Not many kids get to do this; they don't get to plan concerts for big artists."

Hearts4Charity is a faith-based group, with the slogan "Creating for Christ" emblazoned on their T-shirts, but the only requirement for membership is having a passion to help other people.

"We don't all go to the same church. We don't all practice religion. We just do it because we want to," Gildersleeve said.

Most of the 37 youth belonging to Hearts4Charity are Mahtomedi High School students, and most will be seniors. Two middle school students joined the group as well. After college, both Sexson and Gildersleeve foresee jobs in professional charity work.

"I've really fallen in love with everything that charities are all about," Sexson said.