Craft a piece of music that integrates both the suggested theme and letter-based structure.
X:1
L:1/8
Q:1/8=180
M:6/8
K:D
['fed dBc d2 B A2 G FAd', 'fdf a2 a']  
X:1
L:1/8
Q:1/8=180
M:6/8
K:D
|: g | fed dBc | d2 B A2 G | FAd dcd | fee efg | fed dBc | d2 B A2 G | FAd fec | edd d2 :: g | 
 fdf a2 a | fdf a2 a | agg gff | fee efg | fdf a2 a | fdf a2 a | a^gf efg | b3 a2 :|  