Craft a composition that integrates the assigned alphabet-related musical pattern and the provided melodic theme.
X:1
L:1/4
Q:1/2=80
M:4/4
K:G
['a a f g', 'f e A d e']  
X:1
L:1/4
Q:1/2=80
M:4/4
K:G
 a | a f g a | f3/2 e/ d a | a f g a | f3 :: f | e A d e | f3/2 e/ d f | e A d e | f3 f | e A d e | 
 f3/2 e/ d a | a f g a | f3 :|  