Develop a musical composition by integrating the alphabetically represented musical pattern and the supplied melodic theme.
X:1
L:1/8
Q:1/4=100
M:2/4
K:G
['GBAG d2 Bd', 'A3 d ec AB/c/ dBGd cBAG (A/G/F/E/)']  
X:1
L:1/8
Q:1/4=100
M:2/4
K:G
 D | GBAG | d2 Bd | edcB | (A/G/A/B/) AD | GBAG | d2 Bd | edcB | A3 :: d | ec AB/c/ | dBGd | cBAG | 
 (A/G/F/E/) DB/c/ | .d(B/c/) .d(A/B/) | .c(A/B/) .c(d/c/) | B/A/G/A/ BA | G3 |]  