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:G
['ded BGB cBc AGF DGG FGA', 'Bcd eAA dBG FAG FED gfe d^cd']  
X:1
L:1/8
M:6/8
K:G
|: Bc | ded BGB | cBc AGF | DGG FGA | BGB ABc | ded BGB | cBc AGF | DGG FGA |1 BGG G :|2 
 BGG G2 d |: gfe d^cd | edc Bcd | eAA dBG | FAG FED | gfe d^cd | edc Bcd | efg eag |1 fdc d2 d :|2 
 fdc d ||  