Compose a piece of music by integrating the assigned letter representation and provided tune.
X:1
L:1/8
M:2/4
K:G
['GB B/c/B/A/ GB', 'g2 gd g/a/b ag', 'BA/B/ cB/c/ dc']  
X:1
L:1/8
M:2/4
K:G
|: D | GB B/c/B/A/ | GB BA | FA AB/A/ | FA DA | GB B/c/B/A/ | GB dg | f/e/d cA | G2 G :: B/d/ | 
 g2 gd | g/a/b ag | fd de | fg af | g2 gd | g/a/b ag | f/e/d cA | G2 G :: A | BA/B/ cB/c/ | dc AG | 
 FD DE | FG Ac | BA/B/ cB/c/ | dc Ag | f/e/d cA | G2 G :|  