Craft a musical piece in accordance with the designated structure and theme.
X:1
L:1/8
M:2/4
K:none
['BA ^GA', 'z B>A AF E^D E2 BA GF', 'cd (e2'  
X:1
L:1/8
M:2/4
K:none
[K:G] D^C/D/ B>"_c"c | BA ^GA | BA ^GA | AG FG | D^C/D/ B>"_c"c | BA ^GA | BA d>F | GG G z :: 
 B>A AF | E^D E2 | d>"_c"c BA | GF !>!G2 |"_c" c>B AB/c/ | B>A GA/B/ | c/B/A/G/ F/G/A/B/ | 
"_c" .c2"_>Teil A" !>!c2 :|[K:C] E"_f"F (G2 | G)G AB | cd (e2 | e)e d"_c"c | dd B2 | z AG"_f"F | 
 AG (E2 | E)E"_f" FD | E"_f"F (G2 | G)G GB |"_c" cd (e2 | e)e/d/"_c" cA | (A2 A/)"_c"c/B/A/ | 
 (G2 G/)e/d/"_c"c/ | BB/c/ dB |"_c" cc/d/ ec | (A2 A/)"_c"c/B/A/ | (G2 G/)e/d/"_c"c/ | 
 BB/"_c"c/ dB |"_c" cc c z |]  