Well, he's a better singer than Naoya Ogawa (who sang in some bizarre HUSTLE music video...), but isn't Kawada a heel in HUSTLE now? It seems kind of weird for a heel to sing like that. Or was this back while he was still a face?
They dare to let Edge wlak out because he's hurt, so they probably decided to further the heat between him and Hardy (there IS a cross-promotional PPV coming up soon, if I recall correctly). It's actually a rather great idea.