Craft a composition that integrates the assigned alphabet-related musical pattern and the provided melodic theme.
X:1
L:1/8
M:6/8
K:D
['BfB gBf', 'DFB AFC B,DG FDA, B,CD CDE']  
X:1
L:1/8
M:6/8
K:D
 BfB gBf | BfB ecA | BfB gBf | a2 g fdB | BfB gBf | BfB ecA | Bcd cde | dBA B3 || DFB AFC | 
 B,DG FDA, | B,CD CDE | DEF EFG | DFB AFC | B,DG FDA, | B,CD CDE | DB,B, B,3 ||  