Utilizing the provided musical theme and letter-based structure, compose a piece of music.
X:1
L:1/8
M:4/4
K:A
['A2 cA', 'aAag fddf bBba geeg agae fdaf ecdB']  
X:1
L:1/8
M:4/4
K:A
 A2 cA GABc | dcBA GEFG | A2 cA Bcdf | ecdB cAaA | A2 cA GABc | dcBA GEFG | AcEc ABcd | 
 ecdB cA A2 :| aAag fddf | bBba geeg | agae fdaf | ecdB cAAg | aAag fddf | bBba geeg | agae fdaf | 
 ecdB cAAg :|  