Utilizing the provided musical theme and letter-based structure, compose a piece of music.
X:1
L:1/8
Q:3/8=120
M:6/8
K:G
['G2 G BAG F2', 'g f2 d dcd e2 c c2']  
X:1
L:1/8
Q:3/8=120
M:6/8
K:G
 G2 G BAG | F2 G A2 c | B2 B dcB | ABG FED | G2 G BAG | F2 F A2 c | BcB AGF |"^crots" E3 E3 :: 
 g2 e e2 g | f2 d dcd | e2 c c2 e | d2 B BAG | c2 A A2 c | B2 G G2 B | E2 A G2 F |"^crots" G3 G3 :|  