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:Bb
['f2 dB', 'dfbf dfBd Acfc AcF_A']  
X:1
L:1/8
M:4/4
K:Bb
 d | f2 dB f2 dB | A/B/c c>B AFF_A | GEEG FDDd | edcB AcF=e | f2 db f2 dB | A/B/c c>B AFF_A | 
 GBAc Bdce | dfec B2 B || e | dfbf dfBd | Acfc AcF_A | GEEG FDDd | edcB AcFe | dfbf dfBd | 
 Acfc AcF_A | (B/A/B) (A/B/c) (B/c/d) (c/d/e) | (d/e/f) (e/f/g) (f/g/a) bg=e ||  