Construct a musical composition following the given alphabetical structure and incorporating the specified motif.
X:1
L:1/16
M:3/8
K:Bb
['de fdB2 bg fdB2 fd ecAFAc', 'AB cAFAce dBFBdf', 'B2d2f2 fgfed2 c2B2c2']  
X:1
L:1/16
M:3/8
K:Bb
 de | fdB2 bg | fdB2 fd | ecAFAc | e2d2 de | fdB2 bg | fdB2 fd | ecAFAc |{A} B4 :: AB | cAFAce | 
 dBFBdf | gegebg | =efef AB | cAFAce | dBFBdf | gegecA | B4 :: F2 | B2d2f2 | fgfed2 | c2B2c2 | 
 d2B2F2 | B2d2f2 | fgfed2 | c2B2c2 | B4 :|  