I've been watching some live music videos in Arabic and I hear the singers often say something that sounds like "ashou". For example, in this video:
at 2:19, 3:36, 4:55, 6:18, 7:18 the singer says "ashou", which I would interpret as "come on", but at 8:40, while responding to the praises from the audience, where "thank you" could have been expected, he also says "ashou". So, I wonder what exactly does this word mean.