A person is playing an unique instrument.
Bill plays hs glockenspiel.
Not all persons are named Bill.  Not all instruments are a glockenspiel.
exists e1 s1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_instrument(x2) & a_unique(s1) & Theme(s1,x2) & n_person(x1))
exists e1 x1 x2 x3.(ne_nam_bill(x1) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_glockenspiel(x2) & of(x2,x3) & n_h(x3))