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:G
['G3 B', 'A2 g>a b<gg>b a<ff>a g2 gd e>fg>a']  
X:1
L:1/8
M:4/4
K:G
 z2 | G3 B d<BB>c | d<Bg>B d>BA>B | G3 B d<BB>d | (3efg (3dcB A2 :| g>a | b<gg>b a<ff>a | 
 g2 gd e>fg>a | b<gg>b a<f f2 | (3gfe (3dcB A2 g>a | b<gg>b a<ff>a | g2 gd e>fg>a | b>ga>f g>fe>d | 
 (3efg (3dcB A2 |]  