A brown-haired male singing while playing a guitar.
A man strumming on his instrument.
man playing a guitar implies that he is strumming on his instrument.
exists e1 e2 s1 x1 x2 x3.(a_topic(x1) & while(e1,e2) & Theme(e2,x3) & Actor(e2,x2) & v_play(e2) & n_guitar(x3) & Actor(e1,x2) & v_sing(e1) & (x1 = x2) & n_male(x1) & a_brown-haired(s1) & Theme(s1,x1))
exists e1 x1 x2 x3.(a_topic(x1) & on(e1,x3) & n_instrument(x3) & of(x3,x1) & n_male(x1) & Actor(e1,x2) & v_strum(e1) & (x1 = x2) & n_man(x1))