A band is on stage with their instruments.
A band has instruments.
With their instruments means the same as has instruments.
exists p1 x1 x3.(exists x2.(on(x1,x2) & with(x2,x3) & n_stage(x2)) & n_instrument(x3) & of(x3,x1) & n_thing(x1) & n_band(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_have(e1) & n_instrument(x2) & n_band(x1))