Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/8
Q:1/8=125
M:4/4
K:G
['D2 FD', '(3.c.c.d ed']  
X:1
L:1/8
Q:1/8=125
M:4/4
K:G
 D2 FD ADFD | AB{d}cA GECE | D2 (3.F.F.D ADFD | Adde cAGE | D2 FD AD(3.F.F.D | AB{d}cA GE E2 | 
 cABG A3 c |1 (3dcd (3.e.e.d cAGE :|2 (3dcd (3.e.e.d cAGc || Ad(3.d.d.d Ad(3.d.d.d | Adfd edcd | 
 ea{b}ag a3 g | eaab aged | (3.e.f.e ge afge | fded cAGA | B{cdB} c2 B A2 Ac |1 
 (3.c.c.d ed cAGc :|2 (3.c.c.d ed cAGE ||  