Develop a musical creation based on the specified alphabetical structure and given motif.
X:1
L:1/8
Q:1/4=140
M:4/4
K:Bb
['B2 BF DEFD', 'B<B f2']  
X:1
L:1/8
Q:1/4=140
M:4/4
K:Bb
"_Allegro" B2 BF DEFD | B2 BG ABcd | B2 BF DEFD | CccB Accd :| B<B f2 dB f2 | B<B f2 defg | 
 B<B f2 dB f2 | edcB Accd | B<B f2 dB f2 | B<B fB cdeg | fdec dBcA | BGFD Cccd |]  