Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/8
Q:1/2=75
M:2/2
K:A
['eaga eaga', 'ceAe ceAe']  
X:1
L:1/8
Q:1/2=75
M:2/2
K:A
"_NB re key sig" eaga eaga | eaga fedc | dfBf efBf | dfBf fedc | eaga eaga | eaga fedc | 
 ggfe dcBA | E2 G2 A4 :: ceAe ceAe | ceAe fedc | dfBf dfBf | dfBf gfed | ceAe ceBe | ceAe fedc | 
 agfe dcBA | E2 G2 A4 :|  