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:Gmix
['CDF GG,G, CDF', 'ded eff']  
X:1
L:1/8
M:6/8
K:Gmix
|: CDF GG,G, | CDF GDG- | GFE FED | ECC CED | CDF GG,G, | CDF G3 | cBA BAG |1 AFF FED :|2 
 AFF Fze |: dBG g2 a | gdd ded | eff fbb | bc'c' c'fe | dBG g2 a | gdd ded | eff fgf |1 
 ecc c2 e :|2 ecc c3 ||  