Develop a musical composition in line with the given structure and theme.
X:1
L:1/8
M:6/8
K:Bb
['B2 f d B2 e2 c A', 'B3 B2 b b2 f B2 g'  
X:1
L:1/8
M:6/8
K:Bb
 B2 f d B2 | e2 c A F2 | d2 B G E2 | cFA B3 | B2 f d B2 | e2 c A F2 | d2 B GEG | cFA B3 :| 
 B2 b b2 f | B2 g g2 e | A2 f fBA | Gf =e f3 | B2 f d B2 | e2 c A F2 | d2 B GEG | cFA B3 ||  