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:C
['G2 eG GGeG cded cAfA Geee GAcd']  
X:1
L:1/8
M:4/4
K:C
 G2 eG GGeG | cded cAfA | Geee GAcd | e2 ed cAfA | G2 eG GGeG | cded cAfA | Geee GAcd | 
 e2 ed c2 ce | geae geeg | a2 a2 geee | a2 ge eddc | defa geee | geae geeg | a2 ag egag | 
 ageg fdec | dfed cAfA |]  