A large group of people look as if they are in a band, and they are practicing classical music with guitars, violins, and cellos.
Everybody is drinking cocktails.
Everybody can be referring to any group of people and not just this particular group of people.
exists e1 e2 p1 s1 s2 x1 x2 x3 x4 x5 x6 x7.(Theme(e2,x4) & Actor(e2,x3) & v_practice(e2) & subset_of(x7,x4) & n_cello(x7) & subset_of(x3,x4) & with(x3,x5) & rel(x5,x6) & n_violin(x6) & n_guitar(x5) & n_music(x3) & a_classical(s2) & Theme(s2,x3) & n_thing(x3) & n_thing(x3) & exists p2 x8.(in(x3,x8) & n_band(x8)) & as(e1,p1) & Actor(e1,x1) & v_look(e1) & of(x1,x2) & n_people(x2) & n_group(x1) & a_large(s1) & Theme(s1,x1))
all x1.(n_person(x1) -> exists e1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_drink(e1) & n_cocktail(x2)))