A choir dressed in white and black performing on stage.
The people are on stage.
A choir performing on stage is on stage.
exists e1 s1 s2 x1 x2 x3.(on(e1,x3) & n_stage(x3) & in(e1,x2) & n_perform(x2) & a_black(s2) & Theme(s2,x2) & a_white(s1) & Theme(s1,x2) & Theme(e1,x1) & v_dress(e1) & n_choir(x1))
exists p1 x1.(n_people(x1) & exists x2.(on(x1,x2) & n_stage(x2)))