Formulate chord combinations to increase the harmonic complexity of the specified musical excerpt.
"^Allegretto" |: CC DE | FE DC | FE DC | DE F2 | C4- | C4 | CC DE | F2 G2 | 
 A4 |"^(D7)" c4 | GA GF | E2 D2 | C4- | C4 :| |: GG c2- | c3 A | _BA GA | _BA GE | 
 FG F2 | E4- | E4 :|  
X:1
L:1/8
Q:1/4=112
M:2/4
K:C
"^Allegretto""B" |:"C" CC DE | FE DC | FE DC |"G7" DE F2 |"C" C4- | C4 |"C" CC DE |"C7" F2 G2 | 
"F" A4 |"^(D7)" c4 |"G7" GA GF | E2 D2 |"C" C4- | C4 :|"A" |:"C" GG c2- | c3 A | _BA GA | _BA GE | 
"G7" FG F2 |"C" E4- | E4 :|  