Construct a musical piece that follows the designated lettered structure and integrates the provided motif throughout.
X:1
L:1/8
M:4/4
K:D
['f2 df ecAc', 'faec e2']  
X:1
L:1/8
M:4/4
K:D
 g | f2 df ecAc | acAc e2 eg | f2 df ecAc | dBGB d2 dg | f2 df ecAc | acAc e2 eg | f2 ed efge | 
 dBGB d2 dg || faec e2 Ag | faec e2 ef | faec efge | dBGB d2 dg :|  