Utilizing the provided musical theme and letter-based structure, compose a piece of music.
X:1
L:1/8
M:6/8
K:G
['', 'DGG GAG FDE =F2', 'cAG FGA', 'cAG d2 e f2 g a2 g']  
X:1
L:1/8
M:6/8
K:G
 E |: DGG GAG | FDE =F2 E | DGG GFG | Add cAG | DGG GAG | FDE =F2 d | cAG FGA |1 BGG G2 E :|2 
 BGG G2 A |: BcB BAG | ABA AGF | GAG GFG | Add cAG | BcB BAG | ABA ABd | cAG FGA |1 BGG G2 A :|2 
 BGG G2 B |: d2 e f2 g | a2 g fed | cAG FGA | Add cAG | d2 e f2 g | a2 g fed | cAG FGA |1 
 BGG G2 B :|  