Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/16
M:3/4
K:Dmin
['DEFG A4 d4 F2AF D2f2 f2ef gfed']  
X:1
L:1/16
M:3/4
K:Dmin
|:"Dm" DEFG A4 d4 |"Dm" A2BA"A7" G2AG"Dm" F2AF |"Dm" D2f2 f2ef gfed |1,3"A7" ^c2a2 age^c A4 :|2,4 
"A7" age^c"Dm" d8 ::"Dm" A2df a2ba"Gm" g4 |"A7" A2^ce gage"Dm" f4 | 
"Dm" fafd"A7" ege^c"Gm" d2e2 |1,3"E" f2ed"A7" ^c2ec A2>A2 :|2,4"A7"{f} ed^ce"Dm" d8 :|  