Design a musical composition incorporating the alphabetic expression of the chosen structure and the provided melodic theme.
X:1
L:1/16
Q:1/4=112
M:2/4
K:D
['a4{g} f2ef g2f2 e4', 'FAdA GBdB']  
X:1
L:1/16
Q:1/4=112
M:2/4
K:D
 a4{g} f2ef | g2f2 e4 | f2d2d2d2 | edcB A2fg | a4{g} f2ef | g2f2 e4 | f2a2 d2ec | d4 d4 :| 
 FAdA GBdB | FAdA GBdB | d2a2g2f2 | edef e4 | FAdA FAdA | GBdB GBdB | d2f2e2a2 | d4 d4 :|  