A three-piece band is playing a concert.
A trio will be playing their guitars at the concert.
A trio is a three-piece band.   A band playing their guitars are playing in a concert.
exists e1 s1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_concert(x2) & n_band(x1) & a_three-piece(s1) & Theme(s1,x1))
exists e1 x1 x2 x3.(n_concert(x3) & at(e1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_guitar(x2) & of(x2,x1) & n_thing(x1) & n_trio(x1))