MOSTAR, Bosnia-Herzegovina - A few months ago in this southern Bosnian city, some young people snuck into a mosque and played a recording of the British punk rock group "The Sex Pistols" from the speakers at the top of the tall minaret.

What seems to be simply an act of youthful rebellion is perhaps more. In Mostar, nearly four years after the war, music has become not only a way to vent frustrations but a way to heal, to escape the trauma of war and to be normal again.

At this summer's music and arts festival in Mostar, the music mattered more than the city's troubled past. The audience was a mix of young Bosnian Muslims and Bosnian Croats, a mix slowly becoming more common around the city.

But the people of Mostar still are divided. They fought two wars, one against the Serbs and one that turned Croat and Muslim neighbors into enemies. Now Mostar's eastside is largely Croatian and the westside is largely Muslim. The voices of hardline politicians and old prejudices continue to make reconciliation a distant prospect. Yet many people believe music will heal the city.

Orhan Maslo, a Bosnian Muslim, said music helps him cope with the difficulties of life in Mostar after the war. He plays African drums, the djembe and conga, in a band.

"When I play, that's the only thing. It's when I give myself to something, maybe to God, maybe to that drum, when I am completely free and relaxed and I don't care about my problems in that moment. I think that's the best thing, what we all need to do," he said.

Maslo met Teo Krilic during the war and together they struggled to survive..

Even before the war was over, Teo Krilic traded his gun for a guitar.

"I was playing during the war in the frontline, really. I used to bring my guitar, not gun, just guitar," he said. "We didn't want to shoot anymore. It was boring. So, I decided one day I will bring my guitar and we will bring some wine and spirits and we are going to sing and play. It was so loud that Croats - we were just 10, 20 metres (30 to 60 feet) away from each other - started to shoot. Maybe they were scared or angry. I don't know."

Now he shares music with others. He often leads drumming workshops for the patients at a mental hospital near Sarajevo.

Maslo and Krilic have been working at the Pavarotti Music Center in Mostar since it was built nearly two years ago by a British aid group to give people in Mostar a place to play music, receive music therapy, get music lessons, make recordings and reckon with a troubled past.

Much of their work focuses on children. A study by the United Nations Children's Fund found the level of trauma experienced by children in Mostar was the highest documented throughout the former Yugoslavia. Eighty percent of the children in the study said they felt their lives had no value.

Tiffany Hughes, a student from Edinburgh University in Scotland, has been working as a music therapist for four years.

"Music can help children to learn to play again, to have fun again," she said. "Because that's something that was taken away from them for many years. It is also a way for them to be creative again. And often just walking around Mostar, children will follow us in the street singing songs that we've taught them in school."

Though music might have potential to heal the city, it cannot happen without politics. Although the music center is involved in outreach work in schools and hospitals on both sides of Mostar, it is housed on the largely Muslim eastside and has not attracted many Croats.

Many people don't cross the city, fearing they will be harassed when they return. Some receive threats, and young people face pressure from parents who don't want them to cross.

Both men said they were happy to see Croats at the Music festival. Maslo wants to see the city reborn and music might be the only neutral space in Mostar.

"I don't want politics ever to be connected to the music," he said. "I think culture is always 10 years ahead of politics. Culture can always work faster than politics. Always."