Craft a musical composition that adheres to the specified musical theme and letter-based structure.
X:1
L:1/8
M:9/8
K:Amin
['cAc B^GB A2', '^G2 g faf g3 def gdc BA^G']  
X:1
L:1/8
M:9/8
K:Amin
 B | cAc B^GB A2 c | BdB G2 c BdB | cAc B^GB A2 g | ef^g aed c2 :: A | ^G2 g faf g3 | 
 def gdc BA^G | A2 a ^gbg a3 | efg aed cBA | ^G2 g faf g3 | def gdc BA^G | A2 a ^gbg a3 | 
 efg aed c2 ||  