Craft a composition that integrates the assigned alphabet-related musical pattern and the provided melodic theme.
X:1
L:1/8
Q:1/4=150
M:2/4
K:G
['GddB dGdB', 'GBEB GBEB']  
X:1
L:1/8
Q:1/4=150
M:2/4
K:G
 GddB | dGdB | GddB | AFDF | GddB | dGdB | e^cdB | AFDF :: GBEB | GBEB | GBEB | (A/G/F/E/) DF | 
 GBEB | GBEd | e^cdB | AFDF :|  