Design a musical composition incorporating the alphabetic expression of the chosen structure and the provided melodic theme.
X:1
L:1/8
M:2/4
K:D
['AF Dd cA GF/G/', 'cA fd/B/']  
X:1
L:1/8
M:2/4
K:D
|: AF Dd | cA GF/G/ | AF DF | E/F/E/C/ A,F/G/ | AF Dd | cA GF/G/ | Ad ce |1 d2 dF/G/ :|2 d2 de |: 
 fd/B/ Ae/f/ | ge/c/ Ad/e/ | fd/B/ AG/F/ | Ee cA | fd/B/ Ae/f/ | ge cA | fd/B/ Ac |1 d2 de :|2 
 d2 dF/G/ ||  