Design a musical composition incorporating the alphabetic expression of the chosen structure and the provided melodic theme.
X:1
L:1/8
Q:1/2=80
M:2/2
K:G
['G2 G>B', 'dBBG AGAe dBBG B2']  
X:1
L:1/8
Q:1/2=80
M:2/2
K:G
"_No time sig. in ms" D | G2 G>B A>GAB | G>GG>B d2 d>f | G2 G>B A>GA>B | G>EE>D G2 G :| e | 
 dBBG AGAe | dBBG B2 Be | dBBG AGAB | GEED G2 Ge | dBBG AGAe | dBBG B2 Bc | dgBg AGAB | 
 GEED G2 G |]  