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
['BG cGBG', 'G2 g2 dg Bgdg (3gag dg eaaf']  
X:1
L:1/8
M:4/4
K:G
 G2 BG cGBG | AD (3DDD FGAF | (3GGG BG cGBG | Addc BGGD | (3GGG BG c2 (3BBG | AD (3DDD FGAF | 
 (3GGG BG cGBG | Addc BG G2 || g2 dg Bgdg | (3gag dg eaaf | (3ggg dg BgdB | cAdc BG G2 | 
 g2 dg Bgdg | (3gag dg eaaf | (3gfg dg BgdB | c2 dc BGGD ||  