Craft a composition that integrates the assigned alphabet-related musical pattern and the provided melodic theme.
X:1
L:1/8
M:2/2
K:Bb
['B/c/ ded cBc d2 d dcd efe', 'caa dbb dbb age cde', 'f2 [K:Eb] E/F/ [GB]2 [GB] [GB][FB][EB] [GB]3-']  
X:1
L:1/8
M:2/2
K:Bb
 B/c/ | ded cBc | d2 d dcd | efe dcd | e2 e ede | f2 f f=ef | g2 g gfe | dcB FGA | B3- B2 :| 
[K:F] A/B/ | caa caa | dbb dbb | age cde | fed cAB | aaa caa | dbb dbb | age cde | f3- f2 :| 
[K:Eb] E/F/ | [GB]2 [GB] [GB][FB][EB] | [GB]3- [GB][FB][EB] | B,CD EFG | cB=A B2 G | 
 [CA]2 [CA] AGF | [B,G]2 [B,G] GFE | DFD B,CD | [G,E]3- [G,E]2 :|  