Form a musical piece based on the provided motif while observing the defined structure.
X:1
L:1/8
M:2/4
K:G
['AG GB AG']  
X:1
L:1/8
M:2/4
K:G
 B | AG GB | AG GB | AG EB | AG EB | AG GB | AG G z | E>D D>D | E G2 ||  