Utilizing the provided musical theme and letter-based structure, compose a piece of music.
X:1
L:1/8
M:4/4
K:G
['(3DEF G2 BG dGBG']  
X:1
L:1/8
M:4/4
K:G
|: (3DEF |"G" G2 BG dGBG |"Am" ABcd"D" cBAG |"G" Bdgd"Em" egdB |"Am" cBAG"D" FA (3DEF | 
"G" G2 BG dGBG |"Am" ABcd cBAG |"Em" Bdgd"C" egdB |"D" (3cBA FA"G" G2 :: ef |"G" g2 dg Bgdg | 
"C" gabg"D" agef |"G" g2 dg"Em" BgdB |"Am" cBAG"D" FAef |"G" g2 dg Bgdg |"Em" gabg agef | 
"C" gfga gfed |"D" egfa"G" g2 :|  