Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/8
M:4/4
K:Edor
['B3 A', 'gBaB bB B2 aB B2']  
X:1
L:1/8
M:4/4
K:Edor
 B3 A BdAG | EFED E4 | B3 A Bd (e2 | e2) de fedA | B3 A BdAG | EFED E4 | BABd ABAG |1 EFED E4 :|2 
 EFED E2 Bd |: eB B2 eBgB | fB B2 gBaB | bB B2 aB B2 | gBbBaBgB | eB B2 eBgB | fB B2 gBaB | 
 bB B2 aB B2 |1 gfef gfef :|2 gfed e4 ||  