Develop a musical composition using the outlined alphabetical depiction of the structure and the provided theme.
X:1
L:1/8
Q:3/8=90
M:6/8
K:C
['G cdc cGE g>ag gec c3 d', "c'3 c'"]  
X:1
L:1/8
Q:3/8=90
M:6/8
K:C
 G | cdc cGE | g>ag gec | c3 d e>de | A3 B c2 :: G | ceg c'3 c' | bag age | ceg c'3 c' | bag a2 b | 
 c'3 c' bge | b2 a gec | c2 d ede | G2 B2 c2 ||  