Design a musical composition incorporating the alphabetic expression of the chosen structure and the provided melodic theme.
X:1
L:1/16
M:2/4
K:G
['gfed B2>d2 gfed c2>d2 fedc', 'GABc d2d2 GBcd e2e2']  
X:1
L:1/16
M:2/4
K:G
 d2 | gfed B2>d2 | gfed c2>d2 | fedc f2>g2 | e2>f2 d2Bd | gfed B2>d2 | gfed c2>d2 | fedc fgfe | 
 adefg2 ::[K:C] c2 | GABc d2d2 | GBcd e2e2 | gag2 gfd2 | fgf2 fec2 | GABc d2d2 | GBcd e2e2 | 
 gfga gfed | c2e2c2 :|  