Construct a musical composition following the given alphabetical structure and incorporating the specified motif.
X:1
L:1/8
M:2/4
K:D
['f2 fg', 'ed cA', 'ef ge']  
X:1
L:1/8
M:2/4
K:D
|:"^CD: Dual - song" f2 fg | ed cA | f2 fg | e/d/c d2 | f2 fg | ed cA | Ac ef | ge d2 :: ed cA | 
 ed cA | Ac ef | ge d2 | ed cA | ed cA | Ac ef | ge d2 :: ef ge | ed cd | ef ge | ec d2 | ef ge | 
 ed cA | Ac ef | ge d2 :|  