Construct a melodic piece using the designated alphabetic pattern and the provided musical theme.
X:1
L:1/8
M:4/4
K:A
['AFEC A,CEA ceag fedc', 'A2 AB', 'd/c/B fB']  
X:1
L:1/8
M:4/4
K:A
|: AFEC A,CEA | ceag fedc | dBGB dcdf | bagf edcB | AFEC A,CEA | ceag fedc | dBec dBGB |1 
 c2 A2 A2 cB :|2 c2 A2 A2 z B |: BAEA cAce | dBGB dcdB | cAEA cAce | fedc BEG_B | BAEA c2 ce | 
 dBGB dcdB |1 eagf edcB | BAGB A2 AB :|2 eagf eacB | A2 GB A2 AB |: BAeA cAec | cBfB d/c/B fB | 
 agaf eAce | fedc BEGB | BAeA BAec | d/c/B fB d/c/B fB | agaf ecAc |1 BEGB AAAB :|2 BEGB A2 z2 ||  