Develop a musical composition using the outlined alphabetical depiction of the structure and the provided theme.
X:1
L:1/8
M:3/4
K:G
['G2 GA dG d2', 'AB cd e2']  
X:1
L:1/8
M:3/4
K:G
|: G2 GA dG | d2 eg dB | A2 AG AB | D2 DE GD | G2 GA dG | d2 eg d2 | e2 ed ef | g2 de ga | 
 b2 bg fd | e2 ed B2 | Ac BG EA | D2 DE GD | G2 GA dG | d2 c2 B2 | G2 G2 G2 | DE GA G2 :: 
[K:Amin] AF AB cd | e2 de cd | BG dc BG | c2 AB cd | e2 eg ^fd | e2 e2 e2 | Bc BG EG | A2 AB GB | 
 AF AB cd | e2 de cd | BG dc BG | c2 AB cd | e2 eg a^f | e2 GA Bc | d2 c2 B2 | G2 G2 G2 :|  