A orchestra performing a piece.
People are giving a concert.
An orchestra performing a piece may be practicing and not necessarily giving a concert.
exists e1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_perform(e1) & n_piece(x3) & (x1 = x2) & n_orchestra(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_give(e1) & n_concert(x2) & n_people(x1))