Create a composition by utilizing the given alphabet-based musical pattern and the provided melodic theme.
X:1
L:1/8
M:4/4
K:G
['Bc dedB cBAG F2 ED EAGF D2', 'GABG cBcd A2 Bc dedB cBAG F2', 'G2 BA GEDE GABc d2 dd d2']  
X:1
L:1/8
M:4/4
K:G
 Bc | dedB cBAG | F2 ED EAGF | D2 DE GABG || cBcd A2 Bc | dedB cBAG | F2 ED EAGE | D2 DE GBAB | 
 G2 GA G2 :: BA | GEDE GABc | d2 dd d2 cd | edcB cBAB | cBAB c2 B2 | dedB cBAG | F2 ED EAGE | 
 D2 DE GBAB | G2 GA G2 :|  