Contemporary gospel music was given a jolt by the melodic slant of Mary Mary, a sister duo headed for Gary.

“I would say that it is faith-filled, it is fun, it is inspiring,” Mary Mary’s Erica Campbell said of the spiritual material served up by her and her sister, Tina Campbell.

“It’s moving; it’s charged with energy,” Erica Campbell continued. “I think it makes you think and laugh, and want to be better and do better. It’s filled with a lot of strength and confidence.”

In a phone interview this month, Campbell said the road to four Grammy Awards was not always easy for her and Tina: “We were raised really poor growing up, but we believed that great things were ahead of us.”

In 2000, Mary Mary’s “Thankful” was released. The debut album from Erica and Tina won them their first Grammy Award as it grabbed top honor in the Best Contemporary Soul Gospel Album category.

On Friday, Dec. 13, Mary Mary will give Northwest Indiana an up-close-and-personal taste of their inspirational sound at the West Side Leadership Academy in Gary.

The 7 p.m. concert, which takes place in the academy’s West Side Theatre, promises uplifting gems from the duo which burst onto the national scene in 2000 with the trailblazing song “Shackles (Praise You).”

Since Mary Mary’s performance is in Gary, Erica Campbell will get to visit the hometown of pop-music icon Michael Jackson.

“Me and my sister are huge Michael Jackson fans,” she said, noting that “Wanna Be Startin’ Somethin’ “ is a Jackson song that she especially likes.

Mary Mary’s pop sensibilities are reflected in their gospel music, which has incorporated elements of hip-hop and rhythm and blues.

“Tina is a soprano and I’m an alto,” said Campbell, citing the vocal capabilities that are utilized by them.

Mary Mary’s style has proved to have mainstream, crossover appeal that radiates a message.

“We’re Christians; we grew up Pentecostal,” Campbell related. “We tell people your life can be changed by the power of the love of Jesus. I just believe in Jesus.”

Campbell explained that her convictions are not so much about following a certain religion: “I’m about a relationship with God.”

Gary-based Mas Media 7 is presenting Mary Mary’s night of Christian fervor in Gary.

“I think people can expect a vibrant, dynamic performance of contemporary gospel music,” said Mark Spencer, president of Mas Media 7, a producer of shows. “It’s just going to be a rich night of fellowship.”

Friday’s concert, according to Spencer, will feature several opening acts that include local dancers performing an original dance piece choreographed by Asia Dickens of Gary’s West Side Theatre Guild. Another act of note will be Voices of Love, a regional community choir.

Hailing from Inglewood, Calif., Mary Mary takes its name from two biblical figures: Mary, mother of Jesus, and Mary Magdalene.

Having a Christian edge has not prevented Erica and Tina from scoring on Billboard’s mainstream album chart. An example of that national success is 2008’s “The Sound,” which produced the cut “Get Up.”

That song rang up a Grammy Award for Best Gospel Performance.

“Mary Mary,” the singers’ reality show on the WE (Women’s Entertainment) television network, likewise helps to bring the California sisters to an audience not entirely rooted in the Christian music genre.

Erica Campbell said Mary Mary’s music strives to connect with people not already entrenched in Christian beliefs.

“I think it’s more important to reach those who are seeking and searching, and trying to figure their way through life,” she said.