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
['(ag) f2fe fgec dedcd2A2 (3cBA Bc (3edc', 'dcded2 A2 FAdefdAG FA (3def gecA fd']  
X:1
L:1/16
M:2/4
K:G
 (ag) | f2fe fgec | dedcd2A2 | (3cBA Bc (3edc df | edcBA2(ag) | fgfefgaf | (3def (3edc d2Ac | 
 Bdgfedce | dcded2 :: A2 | FAdefdAG | FA (3def gecA | fd (3cdcB2gf | (3efe (3dcB AGFE | FAde fdAF | 
 GBefgecA | (3faf df gece | dcded2 :|  