A female singer and male guitarist on stage.
A band is  performing in public.
just because a female singer and male is on stage they are not said to be band performing in public
exists s1 s2 x1 x2 x3.(a_topic(x1) & on(x1,x3) & n_stage(x3) & n_guitarist(x1) & a_male(s2) & Theme(s2,x1) & of(x1,x2) & n_singer(x2) & a_female(s1) & Theme(s1,x1))
exists e1 x1 x2.(in(e1,x2) & n_public(x2) & Actor(e1,x1) & v_perform(e1) & n_band(x1))