Craft a musical composition that adheres to the specified musical theme and letter-based structure.
X:1
L:1/8
M:4/4
K:A
['cA A/A/A A2 EA A,CEA cAec', 'EAcA eAce fedc']  
X:1
L:1/8
M:4/4
K:A
 e | cA A/A/A A2 EA | A,CEA cAec | dB B/B/B B2 FB | B,DFB dBfd | cA A/A/A A2 EA | A,CEA cAec | 
 defd fgaf | ecdB A2 A || e | (cA)eA EAcA | eAce fedc | (dB)fB (FB)dB | fBdf bged | cAeA EAcA | 
 eAce fedc | defd fgaf | ecdB A2 A2 ||  