Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/8
M:2/4
K:D
['AB c/B/A', 'ed AB c/B/A']  
X:1
L:1/8
M:2/4
K:D
 AB c/B/A | eA cB | AB c/B/A | f2 f2 | AB c/B/A | eA cB | AB c/B/A |1 d2 d2 :|2 d2 de |: fg/f/ ed | 
 fg/f/ ed | AB c/B/A | g2 g2 | fg/f/ ed | fg/f/ ed | AB c/B/A |1 d2 de :|2 d2 d2 |]  