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:Amin
['E ABA a3 gfe g3 c3 edc', 'c2 c']  
X:1
L:1/8
M:6/8
K:Amin
 E | ABA a3 | gfe g3 | c3 edc | Bdg dBG | ABA a2 a | gfe gag | Te3 deg | dBG A2 :: B | c2 c egc | 
 d2 d egB | c2 c edc | Bdg dBG | c2 c egc | deg a2 g | Te3 deg | dBG A2 :|  