Develop a musical composition using the outlined alphabetical depiction of the structure and the provided theme.
X:1
L:1/16
M:2/4
K:Bb
['F2 B2Bc d2cB Bdfg f2(df) bfdf gfdB', 'cedc B2Bc d2cB Bdfg f2(df) gbfd cBcd', 'B2 (BA) G2{A}G^F G2{A}G^F G=FGA B2Bc d2{e}d^c', 'f2(Bd) fgfd f2df gag^f g2bg fdBd cedc']  
X:1
L:1/16
M:2/4
K:Bb
 F2 | B2Bc d2cB | Bdfg f2(df) | bfdf gfdB | cBcd cedc || B2Bc d2cB | Bdfg f2(df) | gbfd cBcd | 
 B2d2 B2 :: (BA) | G2{A}G^F G2{A}G^F | G=FGA B2Bc | d2{e}d^c d2{e}d^c | d=cBd f2(Bd) || fgfd f2df | 
 gag^f g2bg | fdBd cedc | B2d2 B2 :|  