Develop a musical composition using the outlined alphabetical depiction of the structure and the provided theme.
X:1
L:1/8
Q:1/4=120
M:6/8
K:G
['G G2 d d2 c B2 A']  
X:1
L:1/8
Q:1/4=120
M:6/8
K:G
 G | G2 d d2 c | B2 A G2 f | g>ag g>e^d | e3 f3 | g2 f e2 d | c>dB A>Bc | d2 B A>BF | G3 d2 |]  