Compose a piece adhering to the given musical structure and theme.
X:1
L:1/8
M:2/4
K:G
['B/c/ dB cA BGG d/g/', 'Gc Ac G2 f/f/f/f/ dG', 'ag ff B2 fd/f/ ba gg c2'  
X:1
L:1/8
M:2/4
K:G
 B/c/ | dB cA | BGG d/g/ | fAc c/e/ | dGB B/c/ | dB cA | BGG d/g/ | fA c>f |"^ende" ggg ::[K:C] z | 
 ge/c/ Gc | Ac G2 | f/f/f/f/ dG | e/e/e/e/ cG | ge/c/ Gc | Ac G2 | f/f/f/f/ dG | 
"^1. teil, dann 3. teil" ccc :: z | ec/e/ ag | ff B2 | fd/f/ ba | gg c2 | e/g/g/g/ c2 | 
 d/f/f/f/ B2 | gg Be/d/ | cec :|  