In my opinion, if the organization is collecting money for the show for any cause. They should pay singer as they would pay the venue, sound system bla bla bla..If the singer decides to contribute certain percentage of his payment to that same noble cause that is good if not that is his choice. He is not your everyday local singer now. He is a pretty big rock star and it is ok for him to behave like one. Nepali haru je pani freema khojne. Rev