Craft a piece of music that integrates both the suggested theme and letter-based structure.
X:1
L:1/8
M:6/8
K:G
['B2 B BAB cdc BAG', 'AFD AFD', 'fef gag fed']  
X:1
L:1/8
M:6/8
K:G
 G | B2 B BAB | cdc BAG | BAG BAG | Bcd d3 | B2 B BAB | cdc BAG | Bcd efg | BcA G3 :| AFD AFD | 
 dcB AFD | AFD AFD | dcB A3 | AFD AFD | dcB AFD | AFD AFD dcB A3 ||[K:D] f2 f fef | gag fed | 
 fed fed | fga a2 | f2 f fef | gag fed | def efg | ABA d2 ||  