Develop a musical composition by integrating the alphabetically represented musical pattern and the supplied melodic theme.
X:1
L:1/8
Q:1/2=80
M:4/4
K:D
['d2 fa gecA dfed cB A2', 'f2 e2']  
X:1
L:1/8
Q:1/2=80
M:4/4
K:D
 d2 fa gecA | dfed cB A2 | dAdf eAeg | fagf f2 e2 | d2 fa gecA | dfed cB A2 | Bddd Bdgb | 
 agfe d4 :: a2 c'a b2 a2 | bagf f2 e2 | afaf gege | fdd'a f2 e2 | d2 fd d'afd | Adeg fdA^A | 
 Bddd Bdgb | agfe d4 :|  