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:Ador
['EA AB', 'ab ag ef']  
X:1
L:1/8
M:2/4
K:Ador
|: EA AB | cd e2 | G>F GA | GE ED | EA AB | B/c/d ef | g/f/e dB | A2 A2 :: a>g ab | ag ef | 
 g>f ga | ge d2 | ea ab | ag ef | ge dB | A2 A2 :|  