A group of people play instruments and sing.
people are singing
The group of people singing are singing.
exists e1 x1 x2 x3 x4 x5.(Theme(e1,x3) & Actor(e1,x1) & v_play(e1) & n_sing(x5) & n_instrument(x4) & subset_of(x5,x3) & subset_of(x4,x3) & of(x1,x2) & n_people(x2) & n_group(x1))
exists e1 x1.(Actor(e1,x1) & v_sing(e1) & n_people(x1))