Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/8
M:4/4
K:D
['A,B,DE D2 DE F2 BF A4 B3', 'F A2']  
X:1
L:1/8
M:4/4
K:D
|:"D" A,B,DE D2 DE | F2 BF A4 |"G" B3 d BAFE |"D" DEFD"A7" ED B,2 ||"D" A,B,DE D2 DE | 
"D" F2 BF A4 |"G" B3 d BAFE |"A7" DEFE"D" D4 ::"D" F A2 F A2 BA | FEDF ED B,2 |"G" G B2 G B2 GA | 
"G" BAGB AGED ||"D" F A2 F A2 BA |"D" FEDF"Bm" ED B,2 |"D" FEDF ED B,2 |1"A7" A,B,DE"D" FE D2 :|2 
"A7" A,B,DE"D" D4 |]  