Hanging out with youth at a rock show

I'm hanging out at a local rock show with university students. 3-4 bands have already played and 90% of the songs are covers of songs from the states sung in English. There are around 50 people in the small bar. Most people are just tapping to the beat and drinking beers. Some males are smoking. None of the females are smoking. 

The space in front of the band is empty with the crowd forming a half circle. Two girls go into the circle and start to jump around and collide into each other. They are trying to recreate a moshpit - probably something they see in music videos. They giggle as they do it. Then one of their friends joins in (a male) and starts to jump and collide into them. With three people it looks more like a genuine attempt to create a mosh-pit effect. The rest of the crowd is eyeing them as if it was a new kind of behavior they had never seen before.