Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/8
M:4/4
K:G
['edBA GE E2 DEGA', 'AGEF G3 F GABc dBGB A2 (3Bcd']  
X:1
L:1/8
M:4/4
K:G
|: g2 bg edBA | GE E2 DEGA | B3 d g2 fg | eaag agef | gbag edBA | GE E2 DEGA | Bdgb afge |1 
 dBAB G3 f :|2 dBAB Gdef |: g3 f eBdB | cABG AGEF | G3 F GABc | dBGB A2 (3Bcd | e3 B dBAB | 
 GABG AGEG | DEGB AFGE |1 DBAB GDEF :|2 DBAB G3 F ||  