Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/8
Q:1/8=160
M:6/8
K:A
['E[FC]E E2 A FE[FC] E2 e fec', 'e2 e']  
X:1
L:1/8
Q:1/8=160
M:6/8
K:A
 E[FC]E E2 A | FE[FC] E2 e | fec ABc | B2 B BAF | E[FC]E E2 A | FE[FC] E2 e | fec ABc | BAA A3 :| 
 ecB Ace | a2 a faf | e2 e fec | BcB Bcd | e2 e Ace | a2 a faf | e2 e fec | BAA A3 :|  