Create a musical composition using the given alphabetical pattern and melodic theme.
X:1
L:1/8
M:4/4
K:Bb
['B A2 B2']  
X:1
L:1/8
M:4/4
K:Bb
 B3 B A2 B2 | c3 A B2 cd | e3 c d3 B | d2 c3 ^cd=c | B2 _A2 G2 F2 | F2 E2 c3 B | A2 B2 c2 A2 | 
 B4 z4 |]  