Compose a piece adhering to the given musical structure and theme.
X:1
L:1/8
M:3/8
K:G
['G>AG/A/ B2 A']  
X:1
L:1/8
M:3/8
K:G
 G>AG/A/ | B2 A | B>AG/B/ | A2 z | G>AG/A/ | B2 A | G>AG/A/ | B2 A | A>GA/B/ | G2 G | A>BG/A/ | 
 B3 | A>GA/B/ | G2 A | B>AB/A/ | G2 z |]  