Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/8
M:4/4
K:G
['G>B d>g', 'g(g/a/) b>g a>b g<d g>f e/f/e/d/ c/d/c/B/']  
X:1
L:1/8
M:4/4
K:G
 B | G>B G>D G>B d<g | G>B A>G F<D d>F | G>B A>B G>B d>g | a>g b>a g/g/g (g/a/b) | 
 G>B G>D G>B d>g | G>B A>G F<D d>F | G>B A>B G>B d>g | a<g b>a g/g/g g(g/a/) || b>g a>b g<d g>f | 
 e/f/e/d/ c/d/c/B/ A/B/A/G/ FD | b<g a>b gd BG | c>e d>B G/G/G G(g/a/) | (3bgb (3afa (3geg (3fdf | 
 (3ece (3dBG F>A F>D | E<G C>E F>A D>c | B<d Ac BG G ||  