Four men, two of them with guitars, perform on a stage while several people with their hands in the air watch.
Four men are playing pianos for several people.
Guitars and pianos are two different instruments.
exists e1 s1 x1 x2 x3 x4 x5 x6 x7 x8.(n_watch(x7) & of(x7,x8) & n_air(x8) & in(e1,x7) & with(e1,x6) & n_hand(x6) & of(x6,x1) & n_thing(x1) & n_thing(x1) & while(e1,x5) & n_people(x5) & a_several(s1) & Theme(s1,x5) & on(e1,x4) & n_stage(x4) & Actor(e1,x1) & v_perform(e1) & rel(x1,x2) & with(x2,x3) & n_guitar(x3) & of(x2,x1) & n_thing(x2) & card_eq_2(x2) & n_man(x1) & card_eq_4(x1))
exists e1 s1 x1 x2 x3.(for(e1,x3) & n_people(x3) & a_several(s1) & Theme(s1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_piano(x2) & n_man(x1) & card_eq_4(x1))