Compose a piece of music based on the provided motif and adhering to the outlined musical structure.
X:1
L:1/8
M:2/4
K:G
['BAG z']  
X:1
L:1/8
M:2/4
K:G
 GGAA | BAG z | GGA/A/A | BAG z | BBAG | BBBB | AAAG | B2 BB | A/A/AAG | B2 BB | AAAG | B2 BB/B/ | 
 AAAB | G2 G z |]  