Craft a musical piece that abides by the prescribed structural guidelines and the given theme.
X:1
L:1/8
M:9/8
K:G
['GAB BcB', 'GBd gfg'  
X:1
L:1/8
M:9/8
K:G
|: GAB BcB d2 B | GAB BcB G2 E | GAB BcB d2 B | cAA ABG F2 D :: GBd gfg e2 c | GBd gfg d2 B | 
 GBd gfg e2 c | GBd edc BAG :|  