Formulate chord combinations to increase the harmonic complexity of the specified musical excerpt.
A (A/G/) F | B (B/A/) G | e (e/d/) c |1 f (f/e/) d :|2 d d z |: 
 f (f/e/) d | g (g/f/) e | e (e/d/) c | f (f/e/) d | A (A/G/) F | 
 B (B/A/) G | e (e/d/) c | d d z :|  
X:1
L:1/4
M:3/4
K:D
"D" A (A/G/) F |"G" B (B/A/)"Em" G |"A7" e (e/d/) c |1"D" f (f/e/) d :|2"D" d d z |: 
"D" f (f/e/) d |"Em" g (g/f/) e |"A7" e (e/d/) c |"D" f (f/e/) d |"D" A (A/G/) F | 
"G" B (B/A/)"Em" G |"A7" e (e/d/) c |"D" d d z :|  