A group of people are performing on stage.
People are performing on stage.
a group of people is simply more descriptive than people.
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 x1 x2.(on(e1,x2) & n_stage(x2) & Actor(e1,x1) & v_perform(e1) & n_people(x1))