Craft a musical composition that adheres to the specified musical theme and letter-based structure.
X:1
L:1/8
M:4/4
K:Amix
['c2 Ac', 'eAA f eAec A<Aaf eAec fBBf eAec']  
X:1
L:1/8
M:4/4
K:Amix
 d | c2 Ac efed | cAce gBBd | c2 Ac efec | eAec eAA :: f | eAec A<Aaf | eAec fBBf | eAec A<Aae | 
 face eAA :|  