Construct a musical piece that follows the designated lettered structure and integrates the provided motif throughout.
X:1
L:1/4
M:4/4
K:Bb
['G F/G/ A']  
X:1
L:1/4
M:4/4
K:Bb
 G F/G/ A A | B B A2 | G F/G/ A G | F =E D2 | G F/G/ A A | B B A2 | d d/c/ d c | B A G2 |]  