Create a composition by utilizing the given alphabet-based musical pattern and the provided melodic theme.
X:1
L:1/8
M:4/4
K:Bb
['B>c d2', 'B6 D>E F3 D B3 c dBFD']  
X:1
L:1/8
M:4/4
K:Bb
 B>c | d2 F2 F2 d2 | dccB B2 B>c | d2 G2 G2 c2 | BAGF F2 B>c | d2 F2 F2 d2 | dccB B2 B>c | 
 d3 G c3 A | B6 :: D>E | F3 D B3 c | dBFD E3 D | C3 D E3 F | GFFE D2 z d/e/ | f3 d b3 a | 
 gfed e3 f | g3 f f3 A | B6 :|  