an orchestra is playing music.
A couple of musicians having a jam session
an orchestra is contradictory to a  hippy jam session
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_music(x2) & n_orchestra(x1))
exists e1 x1 x2 x3 x4 x5.(a_topic(x1) & Theme(e1,x4) & Actor(e1,x3) & v_have(e1) & n_session(x4) & of(x4,x5) & n_jam(x5) & (x1 = x3) & of(x1,x2) & n_musician(x2) & n_couple(x1))