Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/8
M:4/4
K:Emin
['efed B2 B2']  
X:1
L:1/8
M:4/4
K:Emin
 efed B2 B2 | efed B2 B2 | fgaf A2 d2 | fgaf A3 z | b2 gb a2 fa | g2 eg f3 z | edef gfed | 
 e2 f f2 g2 z2 | efed B2 B2 | efed B2 B2 | dcBA cBAG | FGAF D2 EF | GFGA BABd | edef g2 e2 | 
 dcBA BAGF | E3 DEF E3 z ||  