Utilizing the provided musical theme and letter-based structure, compose a piece of music.
X:1
L:1/8
M:6/8
K:G
['d2 c BAG', 'ABG ABG', 'G3 g2 g f2 f e2 e', 'ABG ABG']  
X:1
L:1/8
M:6/8
K:G
|: d2 c BAG | AGF G2 D | d2 c BAG | AGF G2 :| | ABG ABG | ABG A2 B | c2 B A2 G | FGE D3 | ABG ABG | 
 ABG A2 B | c2 B A2 G | GAF G3 |: g2 g f2 f | e2 e def | gag fgf | e3 d3 :| | ABG ABG | ABG A2 A | 
 c2 B A2 G | FGE D3 | ABG ABG | ABG A2 G | c2 B A2 G | GAF G3 ||  