Craft a composition that integrates the assigned alphabet-related musical pattern and the provided melodic theme.
X:1
L:1/8
Q:1/4=120
M:4/4
K:Bb
['B2 (bg) fdcB', 'BGFE DEFD']  
X:1
L:1/8
Q:1/4=120
M:4/4
K:Bb
"^Reel." F | B2 (bg) fdcB | AFcF dFcF | B2 (bg) fdcB | FBAc dBB :: d | BGFE DEFD | ECC=B cGGA | 
 BGFE DEFD | B,BAc dBB :|  