Construct a musical composition following the given alphabetical structure and incorporating the specified motif.
X:1
L:1/8
M:4/4
K:G
['G2 Bd', 'g2 fg/a/']  
X:1
L:1/8
M:4/4
K:G
 G2 Bd cAFD | G2 Bd c2 cf | gdBd ecAc | BGAF G2 G,2 :: g2 fg/a/ gdBG | g2 fg/a/ g2 b2 |1 
 gdBd ecAc | BGAF G2 G,2 :|2 gdBd ceAc | Bc/d/ DF G2 G,2 ||  