Speaker 1: (singing). In the hymn and prayerbook world of devout America, where gospel music reigns, the praise and worship of the congregation of Washington's Mount Zion Baptist Church is about as racy as it gets. But the world of Christian music isn't what it used to be. It has a new sound, and it goes something like this. (singing). On a warm night in the Pennsylvania countryside, the headline act is in full cry. (singing). The band is called Payable on Death. Despite the name and their appearance, they're self-declared, devoted Christians, a platinum selling alternative rock act, playing at a two day Christian festival called Purple Door. They say God gave them a vision 10 years ago. Now, they're giving it back to thousands of their fans, in a blistering mix of power rock, hip hop and reggae. (singing). Speaker 2: Would you like a programme? Speaker 3: You want a programme? Speaker 4: Yes, please. Speaker 5: Yes. Speaker 4: All the way. Speaker 6: Anyone want three programmes, guys? Speaker 7: Sure. Speaker 6: Great, thanks a lot. Speaker 3: Enjoy your show. Speaker 6: Thank you very much. Have a good evening. Speaker 1: As rock festivals go, this one's about as different as it gets. The fans, mostly teenagers, are dropped off by mum or dad, or they arrive with the local church youth group. While they're here for a good time, they expect to play within the rules. There's no smoking, no booze and no drugs. There are even rules for the bands, the most important, no obscene gestures, no bad language. (singing). Speaker 8: The bands aren't dropping the f-bomb in between each word. Their music, very positive. They're talking about God's love, they're talking about their own experiences and where they've come from, and just their experiences and their own walk with the Lord. Speaker 1: There's no crotch-grabbing going onstage. Speaker 8: No. I hope not, anyhow. Speaker 1: (singing). Even so, it isn't hard to imagine the reaction of conservatives from America's bible belt. But the shock value only adds to the appeal, for performers like [Jeff Fordson]. He says he gave his life to Jesus nine years ago, and counts the Sex Pistols among his music influences. Jeff Fordson: If you act crazy on stage, they go wild to the show. If you act crazy on stage, at some church and not the church you're supposed to act crazy at, the eyebrows are raised. Or maybe you accidentally spit on the stage, but the stage was the altar, and you just spit on their altar. You just run into a lot of things like that. Speaker 10: One, two, three. Crowd: [inaudible]. Speaker 10: Yeah. That's what I'm talking about. Speaker 1: (singing). If the bands have to mind their P's and Q's on stage, their loyal fans have their own code to follow, while moshing or body slamming. They're instructed to help their neighbour up if they fall down, and not to, on any account, try body surfing. Though for the occasional offender, there's always forgiveness, after a good talking to and a hug. Speaker 12: [crosstalk]. Now, go back in there and have some fun, all right? But don't go up. Okay? Thanks, man. Speaker 13: You know sometimes, we even lay scripture on them. You know, just say, "Hey, yeah, we want you to have fun, because God said we can all have fun, but there's time too where you've got to think of the safety of everybody around you". Speaker 14: Haven't you heard your young Christian friends say, "Well, I don't want to be a Christian because the church is full of ... " Crowd: Hypocrites. Speaker 14: Hypocrites, right? [crosstalk] ... Speaker 1: Preaching isn't just the domain of the security guards. In between the music on the three stages of the festival, pastors minister to the punks, rad rockers and metal heads, cool them down between sets. Speaker 14: ... the fact that whatever you learn here, from this weekend, whatever God speaks to your heart, that you would take into your communities and to your work and to your friends and to your family, all that kind of stuff, that you guys would do that. So take it into action. All right? Cool stuff? Okay. Speaker 1: (singing). But as far as the fans are concerned, the really cool stuff is the music, faith-based lyrics served up in rap, hardcore and heavy metal. (singing). While the Christian message can sometimes be lost in the pounding rhythms and screaming vocals, away from the sound stages, it's unmistakable. There's a tent where they're given away pocket gospels. Speaker 15: [crosstalk] and what happens is, we know that every new member will share their faith with 25 people after they leave here. Speaker 16: They're probably not talking about college [crosstalk]. Speaker 1: At another, they're recruiting students for a biblical university. While next door, there's the Rock for Life tent. Mothers and babies with anti-abortion t-shirts, literature and show bags. Speaker 17: We really believe this generation is the generation that's going to turn things around. They're the ones who have already lost one third of their brothers and sisters to abortion. Speaker 1: (singing). Speaker 18: It's a Christian activity, where how many Christians really having a relationship with God and our Lord Jesus? Speaker 19: I'm a Christian. It's the second year I've been here. Speaker 20: Christians don't have to be straight-laced and uptight, as long as they're following the word of God, then God doesn't care what you look like. Speaker 1: God might not care, but the mainstream music industry remains deeply sceptical. No matter the packaging, all that clean-living and praying can't be cool. How tough is it for a band to be tagged as a Christian band in the music industry? Speaker 21: It's very difficult. Obviously, we live with that, because we play these types of events, and there's an association and a stereotype that comes a long with that. Speaker 1: (singing). Which might explain why the bizarre blend of crashing, head-banging music and evangelism is taking off across the United States. It's about as alternative as you can get. (singing). For the thousands of teenagers who've flocked to Purple Door, this is muscular Christianity. This is being a rebel. (singing).