Compose a piece adhering to the given musical structure and theme.
X:1
L:1/16
Q:1/8=120
M:2/4
K:G
['z2 B4 B2GB d2c2 c2>d2 e2d2 defg', 'g2 gf g2d2 g2dg b2a2 g2>f2 e2c2'  
X:1
L:1/16
Q:1/8=120
M:2/4
K:G
"^polka" z2 | B4 B2GB | d2c2 c2>d2 | e2d2 defg | agfa g2f2 | e4 e2>e2 | ed^ce d4 | dfaf dfaf | 
 dfaf g2 :| gf | g2d2 g2dg | b2a2 g2>f2 | e2c2 e2ce | g2g2 efge | dedB G2B2 | dedB G2AB | 
 c2A2 F2>G2 | A2G2 G2 :|  