Craft a musical piece that abides by the prescribed structural guidelines and the given theme.
X:1
L:1/8
M:6/8
K:G
['G2 G GFG ABc B2 e', 'eBe gfe'  
X:1
L:1/8
M:6/8
K:G
 E/F/ | G2 G GFG | ABc B2 e | cBA BAG | AGF E2 F | G2 G GFG | ABc B2 e | BcB AGF | E3 E2 :: B | 
 eBe gfe | ^def Bcd | eBe gfe | faf d2 f |1 eBe gfe | ^def Bba | gfe fe^d | e3 E2 :|2 efg fga | 
 gfe dcB | ABc BAG |{B} AGF E2 |]  