A band playing on a stage.
A marching band is in a parade.
The band is either on a stage or in a parade, they can't be doing both.
exists e1 x1 x2 x3.(a_topic(x1) & on(e1,x3) & n_stage(x3) & Actor(e1,x2) & v_play(e1) & (x1 = x2) & n_band(x1))
exists e1 p1 x1.(exists x2.(in(x1,x2) & n_parade(x2)) & n_band(x1) & Actor(e1,x1) & v_march(e1))