Formulate chord sequences to heighten the harmonic quality of the specified musical portion.
|: G2 BG DG BG | AB cA BG GB | AE AB cB cA | EA AG FD EF | G2 BG DG Bd | 
 cB AB cd ef | ge dB c2 Bc | dB cA BG G2 :: g2 bg dg bg | gb ag fd de | 
 =f2 af cf af | gb ag =fd e^f | g2 bg dg bg | gb ag fd ef | (3gfe dB c2 Bc | 
 dB cA BG G2 :|  
X:1
L:1/8
M:2/2
K:G
|:"G" G2 BG DG BG |"D7" AB cA"G" BG GB |"Am" AE AB cB cA | EA AG"D7" FD EF |"G" G2 BG DG Bd | 
"C" cB AB"D7" cd ef |"G" ge dB"C" c2 Bc |"D7" dB cA"G" BG G2 ::"G" g2 bg dg bg | gb ag"D7" fd de | 
"F" =f2 af cf af |"G" gb ag"D7" =fd e^f |"G" g2 bg dg bg | gb ag"D7" fd ef |"G" (3gfe dB"C" c2 Bc | 
"D7" dB cA"G" BG G2 :|  