I think the sakki line is funny!

But anyway, I'm thinking Japanese people are more respectful, and maybe feel that they should listen intently and quietly when the band is playing? Maybe that's why they cheer after - like they're watching theatre or something.

That's great, but for me, I would think the band would like the audience cheering and appreciation during the songs. That's what makes it a rock concert, and gives the band energy and will which they always say they need to make a good show!