Develop a musical composition using the outlined alphabetical depiction of the structure and the provided theme.
X:1
L:1/8
M:2/4
K:G
['G>A Bc d2 Bd', 'A2 B>A']  
X:1
L:1/8
M:2/4
K:G
 G>A Bc | d2 Bd | c2 B>A | GB D2 | G>A Bc | d2 Bd | cd/c/ BA | G2 G2 :: A2 B>A | GB dB | A2 B>A | 
 GE ED | A2 B>A | GB dB | AB/c/ BA | G2 G2 :|  