Four people stand in front of a stage with microphones.
They are performing a song.
Four people on a stage with microphones may not be performing a song. They could be doing a group interview in front of an audience.
exists e1 x1 x2 x3 x4.(in(e1,x2) & with(x2,x4) & n_microphone(x4) & of(x2,x3) & n_stage(x3) & n_front(x2) & Actor(e1,x1) & v_stand(e1) & n_people(x1) & card_eq_4(x1))
exists e1 x1 x2.(n_thing(x1) & Theme(e1,x2) & Actor(e1,x1) & v_perform(e1) & n_song(x2))