Compose a piece using the alphabetic notation of the assigned musical structure and the provided melodic motif.
X:1
L:1/8
M:4/4
K:Bb
['B2 FD', 'd2 dB', 'B2 deff ffff gaba gfed efgf edcB']  
X:1
L:1/8
M:4/4
K:Bb
 B2 FD B2 FD | BdcB BAGF | GABG GFED | E2 F2 B,4 :: d2 dB d2 dB | defd B2 Bd | c2 cA c2 cA | 
 FGFE D2 B2 :: deff ffff | gaba gfed | efgf edcB | Acgf fedc :|  