Craft a musical work based on the specified structure and given theme.
X:1
L:1/8
Q:3/8=100
M:6/8
K:Bb
['g3 G2 =B c2 C C3 cgc', 'G G3'  
X:1
L:1/8
Q:3/8=100
M:6/8
K:Bb
 g3 G2 =B | c2 C C3 | cgc =bgc | =B2 _A G3 | ceg c_ag | _a2 F F3 | Bdg Bgf | g2 E E3 | BdB BbB | 
 BdB Bb_a | gfe fBd | e2 E E3 || bBB Bdf | f2 F F3 | c'cc cef | g2 G G3 | cgc =bgc | =B2 G G3 | 
 CGC =B,GC | =B,2 A, G,3 | gGc Dc=B | c2 C C3 |]  