An orchestra of about 30 people are practicing on the stage of what appears to be an auditorium full of green chairs.
An orchestra practices for their performance.
The orchestra could be practicing for something other than their performance, such as their final bow.
exists e1 x1 x2 x3.(n_stage(x3) & exists e2 p1 x4.(n_thing(x4) & on(e1,x3) & of(x3,x4) & Topic(e2,p1) & Actor(e2,x4) & v_appear(e2) & exists p2 s1 s2 x5 x6 x7.((x4 = x5) & of(s1,x7) & n_chair(x7) & a_green(s2) & Theme(s2,x7) & Theme(s1,x6) & a_full(s1) & (x5 = x6) & n_auditorium(x5))) & Actor(e1,x1) & v_practice(e1) & of(x1,x2) & n_people(x2) & n_date(x2) & a_date_day_30(x2) & a_date_day_30(x2) & r_about(x2) & n_orchestra(x1))
exists x1 x2 x3.(a_topic(x1) & for(x1,x3) & n_performance(x3) & of(x3,x1) & n_thing(x1) & n_practice(x1) & of(x1,x2) & n_orchestra(x2))