NEW YORK – The rhymes of Jay-Z and Eminem may be burning up the charts, but there's something else that's taking teens — and the business — by storm: Christian music.
"The line between Christian music and rock has shifted so much," said Charles Cross, a music critic and author of Heavier Than Heaven: A Biography of Kurt Cobain. "Even a band like Creed ... They've been able to have mainstream success and a Christian following. It used to be that you couldn't have both."
Sales of mainstream music dropped three percent last year under the burden of sagging sales and rampant Internet piracy, while Christian music sales increased by 13.5 percent, according to the Christian Music Trade Association.
So what saved Christian music from the purgatory of youth group sing-alongs and church retreats? Experts say more accurate methods of tracking sales, a more devout public and, quite simply, better music.
"Most important was when we started participating in SoundScan in 1996," said Frank Breeden, the president of CMTA. "It was the first time our numbers were counted by the same association that counts the rest of music sales."
Christian music used to be almost exclusively available in specialty religious stores. Today, retailers like Kmart and Wal-Mart dedicate whole sections to the genre.
"Our sales were up close to 20 percent this year in Wal-Mart and Kmart," said Breeden. "It's reflective of who consumers in America are. Forty percent of the American population attends church."
The group POD has sold millions and is the poster child for popular crossover Christian bands. But other acts like Sixpence None the Richer and Creed, which isn't explicitly religious, have caught on with secular teens who will listen to music with a spiritual bent.
"Style-wise, the music we do is like any kind of rock show," said Bart Millard, 29, the lead singer for the Christian band MercyMe. "It's pop rock like Dave Matthews or Matchbox 20."
The giveaway for bands like MercyMe comes when listening to the words of their songs, such as "There's a Reason," which openly praise God.
"As Christians, what consumes us is our relationship with Christ," said Millard, who writes most of the band's lyrics. "There may not be a big difference when you first see us [in concert] because there's not that much that differentiates the styles. But what does differentiate us is the lyrics."
And as mainstream labels started hearing the good news about God's music, the American public seemed to open up to the idea of Christian songs, according to Breeden.
"The culture has been more tolerant of religious subject matters," he said.
This summer the first Christian rock touring festival, called Inside Out Soul Festival, hit the U.S. Keith Bosland, 33, a youth pastor from New River Community Church in South Windsor, Conn., took several students to the show.
"There aren't people getting high or drunk, it's cool," he said.
Most of the students in Bosland's youth group don't listen to Christian rock, but he said he was surprised by the teen's interest in even the IOSC bands.
"I thought they wouldn't listen to certain bands," Bosland said. "When one of the guys said he wanted to see Michael W. Smith, which is basically worship and praise music, that was definitely a surprise to me."
But what do Christian musicians think of their mainstream competitors with less than heavenly lyrics?
"Eminem has a God-given talent that he's not using for God," said Millard. "I 100 percent don't agree with what he does, but he is amazingly talented."
Still, explicitly religious bands aren't about to land on Total Request Live or bump Eminem off the charts, said Cross. "Christian music is doing better, but whether its taking away from the secular segment, that's impossible to know."
However, he added that music that touches serious topics will always be popular.
"There's only so far any songwriter can go with girls and boys and cars," Cross said. "Big issues like life and death must be explored."