Create a musical composition based on the alphabetic representation of the predetermined pattern and the given melodic theme.
X:1
L:1/8
M:4/4
K:G
['cABG AGEG', 'g3 a bgaf gfed B2']  
X:1
L:1/8
M:4/4
K:G
|: Bd | gedB G2 AB | cABG AGEG | DGBd g2 fg | eaag fdef | gedB G2 AB | cABG AGEG | cABG AGEG | 
 DGGF GABd :: g3 a bgaf | gfed B2 AG | EAAB cBAG | (3EFG AB cdef | g3 a bgaf | gfed B2 AB | 
 cABG AGEG | DGGF GABd :|  