Develop a musical composition using the outlined alphabetical depiction of the structure and the provided theme.
X:1
L:1/8
Q:1/8=150
M:3/4
K:G
['GB B2 GB dc Bd ed cB', 'BG EF']  
X:1
L:1/8
Q:1/8=150
M:3/4
K:G
 GB dc"^*" B2 | GB dc Bd | ed cB A2 | BG GD EG :: BG EF G2 | BG EF GA | BG EF G2 | AB cB FD :|  