One man sings while another plays guitar during a stage show.
A singer and a guitar player perform at a benefit concert.
Just because it is a stage show doesn't mean it is a benefit concert.
(x)
exists e1 x1 x2 x3 x4 x5 x6.(at(e1,x5) & n_concert(x5) & of(x5,x6) & n_benefit(x6) & Actor(e1,x1) & v_perform(e1) & subset_of(x3,x1) & n_player(x3) & of(x3,x4) & n_guitar(x4) & subset_of(x2,x1) & n_singer(x2))