Develop a musical piece that combines the given theme and letter-structured outline.
X:1
L:1/8
M:4/4
K:D
['', 'gB B2', 'GFED E2 EF GFED']  
X:1
L:1/8
M:4/4
K:D
 ef |: gB B2 gBaB | gB B2 gfed | cAeA fAeA | cAef gfef | gB B2 gBaB | gB B2 gfed | cdef gfec |1 
 dfec d2 ef :|2 dfec d2 DE |: F2 AF GFED | F2 AF GFED | E2 EF GFED | E2 EF GFED | F2 AF GFED | 
 F2 AF GFED | cdef gfec |1 dfec d2 DE :|  