People are marching in a parade while beating drums and playing instruments.
People are playing music on stage.
People can't be marching in a parade while playing music on stage.
exists e3 e2 e1 x1 x2 x3 x4.(while(e1,e3) & Theme(e3,x4) & Actor(e3,x1) & v_play(e3) & n_instrument(x4) & while(e1,e2) & Theme(e2,x3) & Actor(e2,x1) & v_beat(e2) & n_drum(x3) & in(e1,x2) & n_parade(x2) & Actor(e1,x1) & v_march(e1) & n_people(x1))
exists e1 x1 x2 x3.(on(e1,x3) & n_stage(x3) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_music(x2) & n_people(x1))