A lady playing music on her harp.
The woman is playing in an orchestra.
A woman does not have to be a lady.  A lady playing music on her harp does not have to be in an orchestra.
exists e1 x1 x2 x3 x4.(a_topic(x1) & on(e1,x4) & n_harp(x4) & of(x4,x1) & n_female(x1) & Theme(e1,x3) & Actor(e1,x2) & v_play(e1) & n_music(x3) & (x1 = x2) & n_lady(x1))
exists e1 x1 x2.(n_woman(x1) & in(e1,x2) & n_orchestra(x2) & Actor(e1,x1) & v_play(e1))