>> we were actually filming in another area of the prison. and we heard some music. it took us over, and there was a heavy metal rock band in a little room rehearsing and playing. and i think that was one of the elements that the staff thought was good for the inmates. to spend time blowing off steam. >> though it's not a common sight, we visited american prisons with band rooms, as well. but one aspect of the inmate population provided the most striking difference of all. >> the eastern european prisons, it was predominantly caucasian inmates. whereas in american prisons, there are a variety of ethnicities, a lot of tensions exist between the ethnicities. >> but only one group at mirov stands out as a minority. they're called roma. a nomadic ethnic minority that has taken root throughout eastern european nations.