Craft a piece of music that integrates both the suggested theme and letter-based structure.
X:1
L:1/8
M:2/2
K:G
['g2 dc', 'dega b2 ag agab']  
X:1
L:1/8
M:2/2
K:G
 d | g2 dc BGdB | cAeA cAAf | g2 dc BGdG | FEDC B,G,G, :| e | dega b2 ag | agab geeg | dBgB cBAG | 
 AGBA GEEe | dega b2 ag | agab geed | egdb caBg | EADF GB,B, ||  