Develop a musical composition using the outlined alphabetical depiction of the structure and the provided theme.
X:1
L:1/8
M:4/4
K:G
['g2 gf gdga bage dBGA', 'G2 GF GABd']  
X:1
L:1/8
M:4/4
K:G
 (3def | g2 gf gdga | bage dBGA | Bd G2 Bd GA | BGcB AGED | g2 gf gdga | bage dBGA | Bdge dBAB | 
 G2 GG G2 :| (3DEF | G2 GF GABd | edgf edBd | edge dBGA | BGcB AGED | G2 GF GABd | edge dBGA | 
 Bdge dBAB | G2 GG G2 :|  