Craft a musical piece that abides by the prescribed structural guidelines and the given theme.
X:1
L:1/8
M:9/8
K:G
['GAG G2 e', 'FED dBd'  
X:1
L:1/8
M:9/8
K:G
 D | GAG G2 e dBG | E2 A ABG FED | GAG G2 e def | g2 G GAG FED :: dBd edg dBG | E2 A ABG FED | 
 dBd ece def | g2 G GAG FED :|  