chanting

Although the wall between my apartment and the one next door is mostly cement, there's an air vent that seems to connect the two, the result being that I can clearly hear what goes on over there. And chanting seems to be what's going on. Every Friday night, and then scattered throughout the weekend, it sounds like of group of several guys over there chanting loundly. It's not a Gregorian-type chant, but rather a fast-paced one with not a lot of rhythm, or perhaps a fairly complex one. I can't tell what language it is, but it sounds like Arabic, African, or possibly even Hebrew.