A group of people with instruments are on stage.
The people have musical instruments with them.
Group of people are people, and musical instruments are types of instruments.
exists p1 x1 x2 x3.(exists x4.(on(x1,x4) & n_stage(x4)) & of(x1,x2) & with(x2,x3) & n_instrument(x3) & n_people(x2) & n_group(x1))
exists e1 s1 x1 x2.(n_thing(x1) & n_people(x1) & Theme(e1,x2) & Actor(e1,x1) & v_have(e1) & with(x2,x1) & n_instrument(x2) & a_musical(s1) & Theme(s1,x2))