Create a musical composition using the given alphabetical pattern and melodic theme.
X:1
L:1/8
M:4/4
K:G
['BcdB G2', 'd2 gfga b2 b2 abag f2 d2']  
X:1
L:1/8
M:4/4
K:G
 BcdB G2 gf | edef gedc | BcdB G2 Bd | cBAG F2 D2 | BcdB G2 gf | edef gdef | gfge dedc | 
 BGAF G2 d2 :: gfga b2 b2 | abag f2 d2 | edef gdBd | cBAG F2 D2 | GFGB AGAc | BGBd edef | 
 gfge dedc | BGAF G4 :|  