A group of people are performing on stage.
A group is performing for a charitable event.
just because they are performing on stage does not mean it is a charitable event.
exists e1 x1 x2 x3.(on(e1,x3) & n_stage(x3) & Actor(e1,x1) & v_perform(e1) & of(x1,x2) & n_people(x2) & n_group(x1))
exists e1 s1 x1 x2.(for(e1,x2) & n_event(x2) & a_charitable(s1) & Theme(s1,x2) & Actor(e1,x1) & v_perform(e1) & n_group(x1))