. >> singing is an important part of culture in many balkan countries, and bulria is no exception. dunghe lonyearof ottoman rule, the songs give the bulgarians a feeling of belonging together. even today, there is acquired in almost every community, like in this town in the heart of the country -- there is a choir in almost every community. not everyone is happy when the men from the local quire turn up at their doorstep. >> they are called the black angels. they regularly venture forth to ensure that law and order is maintained here in their town. there employer is the town's mayor. the town is known for being home to bulgaria's largest weapons factory, but it is nearly bankrupt and owes millions of euros in unpaid taxes. that is not all. the town but the tax officer says many citizens are also in arrears, said the mayor made the black angels his tax collectors. >> i am very pleased with the black angels. they are a real success appear at firstthey were bringing in up to 40,000 level oa wk, about 20,000 euros. now, sometimes they collect as much as 30,000 euros, and very quickly a