Construct a musical piece that follows the designated lettered structure and integrates the provided motif throughout.
X:1
L:1/8
M:6/8
K:C
['cec GEC', '(e/f/) gec AdB ecc c2']  
X:1
L:1/8
M:6/8
K:C
|:!f! cec GEC | Add d2 d |!p! cec GEC | ecc c2 c |!f! cec GEC | Add d2 d |!p! cec GEC | ecc c2 z :: 
!f! gec dBG | gec dBG |!p! agf edc | BGG G2 G |!f! cdc cAA |!p! ded !fermata!d2 (e/f/) | 
!f! gec AdB | ecc c2 z :|  