Compose a piece of music following the given alphabetical representation of the musical structure and the provided motif.
X:1
L:1/4
Q:1/4=88
M:2/4
K:Bb
['B, B,']  
X:1
L:1/4
Q:1/4=88
M:2/4
K:Bb
 B, B, |[M:3/4] F F |[M:2/4] E/ D/ C/ B,/- B, | B, B, |[M:3/4] C C |[M:2/4] B,/ A,/ G,/ F,/- F, | 
 B, B, |[M:3/4] C C |[M:2/4] B,/ A,/ G,/ F,/- F, |[M:3/4] B, B, C C | B,/ A,/ G,/ F,/- F, |]  