Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/8
M:2/4
K:G
['fABA fABA d2 e>f', 'fa f>e edBA d2 e>f']  
X:1
L:1/8
M:2/4
K:G
 fABA | fABA | d2 e>f | edBA | fABA | fABA | d2 e>f | ed d2 :: fa f>e | edBA | d2 e>f | edBA | 
 fa f>e | edBA | d2 e>f | ed d2 :|  