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
['a2 af/a/ ba fa g>f ge a3', 'e=f fd df ed B/d/B Af fe/f/']  
X:1
L:1/8
M:2/4
K:D
|: a2 af/a/ | ba fa | g>f ge | a3 g | fd de/f/ | gf ed | cA Bc |1 de fg :|2 d2 c>B |: Af fe/f/ | 
 gf e=f | fd df | ed B/d/B | Af fe/f/ | gf ed | cA Bc |1 d2 c>B :|2 de fg ||  