Acapella / Human Beatbox Group On Paris Metro

I've traveled over in Europe a few times, riding on subways to get around in the larger cities. I've seen a lot of street musicians ride them and play between stops for tips. Officially they are not allowed to do this, so usually they can only play half a song before they run off to another train to avoid getting caught. Some of 'em are pretty good, but not as good as this group (although I'm no Phil Collins fan)...