Develop a musical composition using the outlined alphabetical depiction of the structure and the provided theme.
X:1
L:1/8
Q:1/2=60
M:2/2
K:G
['gG G/G/G', 'E f .gd.dg .ae.ef .gd.de g/f/g/a/ ba']  
X:1
L:1/8
Q:1/2=60
M:2/2
K:G
 g | gG G/G/G BAAB | gG G/G/G gaba | gG G/G/G BA-AB | GEFD E2- E :: f | .gd.dg .ae.ef | 
 .gd.de g/f/g/a/ ba | .gd.dg .aeef | g/(a/b) a>g e2 e :|  