Create a composition by utilizing the given alphabet-based musical pattern and the provided melodic theme.
X:1
L:1/4
M:3/4
K:G
['D D']  
X:1
L:1/4
M:3/4
K:G
 D D D | D D/>A/ G3/2 _B/4A/4 | G z2 | _B/c/ | d _e d | c d c/_B/ | A2 d2 | _e d/c/ c A/c/ | 
 _B A G | B | A d G/G/F/A/ | G2 d2 | _e d/c/ c A/c/ | _B A G | B | A d G/G/F/A/ | G2 z2 | z |]  