Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/8
M:6/8
K:D
['DFA dcd e2 d B3', 'f2 e']  
X:1
L:1/8
M:6/8
K:D
|: DFA dcd | e2 d B3 | DFA DFA | G2 F E3 | DFA dcd | e2 d B3 | ABA GFE | DFA d3 :: f2 e dBA | 
 Bcd A3 | dcd e3 | f3 g3 | f2 e d2 A | Bcd A3 | ABA GFE | DFA d3 :|  