Craft a piece of music that integrates both the suggested theme and letter-based structure.
X:1
L:1/16
M:2/4
K:G
['D2 G2GF GBdB A^GAB cdef gfgf ecAG', '', 'GBdB A^GAB cdef gfgf ecAF G2G2', '', 'Bcdf efed ^cdef gfgf ecAG FGAF']  
X:1
L:1/16
M:2/4
K:G
"^A" | D2 | G2GF GBdB | A^GAB cdef | gfgf ecAG | FGAF DEFD |]"^B" |] GFEF GBdB | A^GAB cdef | 
 gfgf ecAF | G2G2 G2 |]"^C" |: (Bc) | dedc Bcdf | efed ^cdef | gfgf ecAG | FGAF DEFD |]  