Formulate chord combinations to increase the harmonic complexity of the specified musical excerpt.
|: G3 D E3 G | AGAB d2 Bd | (3efged BAGA | BAGE ED D2 | G3 D E3 G | 
 AGAB d2 Bd | (3efged BAGA | BAGE ED D2 :: ea a2 efge | dBBA B2 Bd | 
 ec B2 eBgB | eB B2 dBAB | ea a2 efge | dBBA B2 Bd | (3efged BAGA | 
 BAGE ED D2 :|  
X:1
L:1/8
M:4/4
K:G
|:"G" G3 D"Em" E3 G |"C" AGAB"D" d2 Bd |"Em" (3efged BAGA |"C" BAGE"D" ED D2 |"G" G3 D"Em" E3 G | 
"C" AGAB"D" d2 Bd |"Em" (3efged BAGA |"C" BAGE"D" ED D2 ::"Am" ea a2 efge |"Bm" dBBA B2 Bd | 
"Em" ec B2 eBgB | eB B2"C" dBAB |"Am" ea a2 efge |"Bm" dBBA B2 Bd |"Em" (3efged BAGA | 
"C" BAGE"D" ED D2 :|  