Formulate chord sequences to heighten the harmonic quality of the specified musical portion.
|: d | gg ag | f3 d | aa ba | g3 B | dd eB | d c2 g | ff fe/f/ | g2 g :|  
X:1
L:1/8
M:2/4
K:G
|: d |"G" gg ag |"D7" f3 d | aa ba |"G" g3 B | dd eB |"C" d c2 g |"D7" ff fe/f/ |"G" g2 g :|  