Develop a musical composition incorporating the given motif while adhering to the outlined alphabetical form.
X:1
L:1/4
Q:3/4=100
M:6/4
K:Bb
['B c', 'A B']  
X:1
L:1/4
Q:3/4=100
M:6/4
K:Bb
 F | B c d d f d | B c d{e} d2 c | B c d d f d | A B c{d} c2 F | B c d d f d | g a b =e2 e | 
 d =e f g f e | f2 F F2 :: F | A B c c d c | c G B A2 G | F D F G A B | f e d c2 F | B c d G A B | 
 c d e A G F | G A B c B A | B2 B, B,2 :|  