Design a musical composition incorporating the alphabetic expression of the chosen structure and the provided melodic theme.
X:1
L:1/8
M:4/4
K:Amix
['e/e/e eg f2 fa', 'efed c2 Ac']  
X:1
L:1/8
M:4/4
K:Amix
 A | e/e/e eg f2 fa | e2 ed cAAc | e/e/e eg f2 fa | B2 d/c/B/A/ BGGB | e/e/e eg f2 fa | 
 e2 ed cAAc | d2 fd c2 ac | B2 d/c/B/A/ BGG || B | efed c2 Ac | efed cAAc | efed c2 Ac | 
 B2 d/c/B/A/ BGGB | efed c2 Ac | efed cAAc | d2 fd c2 ac | B2 d/c/B/A/ BGG ||  