Develop a musical piece employing the provided motif and an alphabet-based structure.
X:1
L:1/8
Q:1/2=90
M:3/2
K:Bmin
['Bcde f2 f2 f4 gfed cdcB ^A2', 'B2 defg a2 a2 a4 bagf efed']  
X:1
L:1/8
Q:1/2=90
M:3/2
K:Bmin
 Bcde f2 f2 f4 | gfed cdcB ^A2 F2 | B2 F2 EFGF E2 DC | B,2 B4 d2 c2 B2 :| defg a2 a2 a4 | 
 bagf efed c2 Bc | d2 A2 ABAG FGFE | D2 d2 fedc d3 e | fgab agfe d4 | efga gfed c4 | 
 defg f2 f2 f4 | F2 B2 B2 d2 c2 B2 :|  