Develop a musical composition using the outlined alphabetical depiction of the structure and the provided theme.
X:1
L:1/8
M:6/8
K:G
['D3 BAG ABA']  
X:1
L:1/8
M:6/8
K:G
|:"G" G3 GAB |"C" AGE"D" GED |"G" GFG"Am" AGE |"C" GED"D" DEF ||"G" G3 GAB |"C" AGE"C/B" GAB | 
"Am" cBA"C" BGE |"D" DED |1 DEF :|2 D3 |:"C" cBA"G" BAG |"D" ABA AGE |"C" cBA"G" BGE |"D" DED D3 || 
"C" cBA"G" BAG |"Am" ABA ABc |"D" dcA"C" GEA |1"D" DED D3 :|2"D" D2 B cAF |]  