A group of musicians perform on the street for donations.
A group of harmonica players are performing on the street.
Sentence two may be talking about different group.
exists e1 x1 x2 x3 x4.(n_street(x3) & on(e1,x3) & for(x3,x4) & n_donation(x4) & Actor(e1,x1) & v_perform(e1) & of(x1,x2) & n_musician(x2) & n_group(x1))
exists e1 x1 x2 x3 x4.(n_street(x4) & on(e1,x4) & Actor(e1,x1) & v_perform(e1) & of(x1,x2) & n_player(x2) & of(x2,x3) & n_harmonica(x3) & n_group(x1))