A group performs on stage.
A group of people are up on stage.
Both subjects are on a stage
exists e1 x1 x2.(on(e1,x2) & n_stage(x2) & Actor(e1,x1) & v_perform(e1) & n_group(x1))
exists p1 s1 x1 x2.(a_up(s1) & Manner(p1,s1) & exists x3.(on(x1,x3) & n_stage(x3)) & of(x1,x2) & n_people(x2) & n_group(x1))