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
['def g2 a bag afd', 'G2 (G/A/) c3 dcB cAG F3 DED'  
X:1
L:1/8
M:6/8
K:G
 (G/F/) |"G" D2 G G2 A | B2 d cAG |"D" F2 D DED |"D" F2 F"C" (E2 D) |"G" D2 G G2 A | BAG Ade | 
"D" fed cAF |"G" AGG G2 :: (B/c/) |"G" def g2 a | bag afd |"D" fef afd | (d>ef/g/) afd | 
"G" def g2 a | bag afd |"D" fed cAF |"G" AGG G2 :: (G/A/) |"G" B3"C" c3 |"G" dcB cAG |"D" F3 DED | 
 FEF AFD |"G" B3"C" cBc |"G" dcB cde |"D" fed cAF |"G" AGG G2 :|  