A man is playing an instrument.
A man on a nightclub stage holding something.
Just because the man is playing an instrument doesn't mean he is on a nightclub stage.
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_instrument(x2) & n_man(x1))
exists e1 s1 x1 x2 x3 x4.(a_topic(x1) & Theme(e1,x4) & Actor(e1,x3) & v_hold(e1) & n_thing(x4) & (x1 = x3) & on(x1,x2) & n_stage(x2) & a_nightclub(s1) & Theme(s1,x2) & n_man(x1))