Create a series of chord progressions to improve the harmonic structure of the given music piece.
|: G>A BB cBAc | BAGF E2 D2 | G>A BB cBAc | BGAF G2 G2 :| |: d c/B/ AB c B/A/ GB | 
 AGFG A>B A2 | d c/B/ AB c B/A/ GB | AGGF G2 G2 :|[K:F] |: B/A/ G B/A/ G FG A2 | DEFG ABAG | 
 B/A/ G B/A/ G FG A2 | DEFG GF G2 :|  
X:1
L:1/8
Q:1/4=127
M:4/4
K:G
"A" |: G>A BB cBAc | BAGF E2 D2 | G>A BB cBAc | BGAF G2 G2 :|"B" |: d c/B/ AB c B/A/ GB | 
 AGFG A>B A2 | d c/B/ AB c B/A/ GB | AGGF G2 G2 :|[K:F]"C" |: B/A/ G B/A/ G FG A2 | DEFG ABAG | 
 B/A/ G B/A/ G FG A2 | DEFG GF G2 :|  