Craft a composition that integrates the assigned alphabet-related musical pattern and the provided melodic theme.
X:1
L:1/8
M:4/4
K:G
['BdcA Bddc BdcA', 'faaf gbag']  
X:1
L:1/8
M:4/4
K:G
 BdcA Bddc | BdcA BGGA | BdcA Bdde | fdcA BG G2 | BdcA Bddc | BdcA BG G2 | BdcA BddA | 
 BdcA G2 G2 :| faaf gbag | gfdc ABcA | faaf gbag | fdcA G2 G2 | faaf gbag | gfdc ABcA | bgfa gfdc | 
 defa g2 g2 :|  