Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/16
M:2/4
K:D
['dcde dAFG ABAF A2de', 'd2 f2 fa2f a2a2 fa2f a4 gb2g']  
X:1
L:1/16
M:2/4
K:D
 fe | dcde dAFG | ABAF A2de | f2fg fede | feef e2fe | dcde dAFG | ABAF A2de | fa2b afde | 
 fddc d2 :: f2 | fa2f a2a2 | fa2f a4 | gb2g b2b2 | gb2g b2bc' | d'2d'2 a2a2 | fgfd e2de | 
 fa2b afde | fddc d2 :|  