Produce a music piece that aligns with the mentioned musical structure and theme.
X:1
L:1/8
Q:1/2=90
M:2/2
K:Bb
['f2 d2 cB c2 BA B2 B,2', 'B,2 FE DF B4 dc =Bc d2'  
X:1
L:1/8
Q:1/2=90
M:2/2
K:Bb
 f2 | d2 cB c2 BA | B2 B,2 D2 B,2 | DE F2 B2 d2 | (gf)(ed) (ed)(cB) | AB c4 f2 | d2 cB c2 BA | 
 B2 B,2 D2 B,2 | DF B4 AG | (FE)(DC) B,2 || FE | DF B4 dc | =Bc d2 G2 g2 | e2 c2 G2 c2 | 
 =BcdB c2 c_B | Ac f4 BA | GB e4 gf | (ef)(gf) (ed)(cB) | AG F2 z2 f2 | (ge)(dc) (fd)(cB) | 
 dB b4 d2 | edcB c2 BA | B6 |]  