Construct a musical composition utilizing the provided motif and conforming to the specified structure.
X:1
L:1/8
M:4/4
K:Bb
['B,<B B>c d<B B2 C<c c>d e<c', 'dB G2'  
X:1
L:1/8
M:4/4
K:Bb
 B,<B B>c d<B B2 | C<c c>d e<c c2 | d<(f f>g) fbdB | F>B A/B/c/A/ d<B B2 :| B/c/ | dBec dB G2 | 
 FBGB A(cc)B/c/ | dBec dB G2 | (F>B) A/B/c/A/ d<(B B) B/c/ | DBec dB G2 | FBGB A(cc)B/c/ | 
 d<f f>g f<b d2 | (F<B) A/B/c/A/ d<B B ||  