Develop a musical composition using the outlined alphabetical depiction of the structure and the provided theme.
X:1
L:1/8
M:4/4
K:Amix
['A<A Bc a>g fe e<e cA cB/c/', 'fa e>c BA']  
X:1
L:1/8
M:4/4
K:Amix
 A<A Bc a>g fe | e<e cA cB/c/ BG | A>A AA Bc e<e | fa e>c BA A<A :: e<e fa e>c BA | 
 A<A Bcc B/c/ BG | A<A Bc a>g fe | fa e>c BA A<A :|  