A crowd is watching a teenager perform.
Someone is on a stage.
One can perform without being on a stage.
exists e2 e1 x1 x2 x3.(Actor(e2,x1) & v_perform(e2) & Theme(e1,x3) & Actor(e1,x2) & v_watch(e1) & n_teenager(x3) & (x1 = x2) & n_crowd(x1))
exists p1 x1.(exists x2.(on(x1,x2) & n_stage(x2)) & n_person(x1))