Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/8
M:4/4
K:Dmix
['D2 (3FED FGAB (c2 c)d cA G2', 'A2 e(aa)g abag eaag ed d2 e(gg)f']  
X:1
L:1/8
M:4/4
K:Dmix
|: D2 (3FED FGAB | (c2 c)d cA G2 | Add^c d2 cd | ed^cd eddA | D2 (3FED FGAB | (c2 c)d cA G2 | 
 ABAG EGAB |1 cAGc EDDC :|2 cAGc ED D2 |: e(gg)f g2 ed | cded cA A2 | e(aa)g abag | eaag ed d2 | 
 e(gg)f g2 ed | cded cA G2 | ABAG EGAB |1 cAGc ED D2 :|2 cAGc EDDC ||  