Formulate a musical piece by utilizing the specified motif and alphabet-based structure.
X:1
L:1/8
M:4/4
K:D
['d2 ef/g/', 'fa/f/ eg']  
X:1
L:1/8
M:4/4
K:D
 AddB A2 Ac | BGAF GFED | FAAF GFED |1 d2 ef/g/ fdec :|2 d2 ef/g/ fd d2 || faag fddf | gfga beeg | 
 faag fddg | fa/f/ eg fd d2 | faag fddf | gfga beeg | fgaf bgag | fa/f/ eg fdec ||  