Design a musical composition incorporating the alphabetic expression of the chosen structure and the provided melodic theme.
X:1
L:1/8
M:6/8
K:Eb
['EFG AGF GFE', 'B3 Bcd e2 d cBA G2 d']  
X:1
L:1/8
M:6/8
K:Eb
 EFG AGF | GFE B2 G | ABc BAG | G3 F3 | EFG AGF | GFE e2 e | cdB =ABc | c3 B3 || Bcd e2 d | 
 cBA G2 d | edc =Bcd | d3 c3 | _Bcd eBc | BAG F2 E | EGA BGc | F3 E3 ||  