Design a musical composition incorporating the alphabetic expression of the chosen structure and the provided melodic theme.
X:1
L:1/4
M:3/4
K:C
['e c2']  
X:1
L:1/4
M:3/4
K:C
 G c e | f d2 | e c2 | G c2 | e g g | a f2 | a a3/2 g/ | e g3/2 a/ | f d d | e c2 | e c2 | 
 G g3/2 e/ | f d d | e c2 | e c2 | G c2 |]  