Develop musical pieces by incorporating the given chord changes.
'D', 'G', 'D', 'A', 'D', 'G', 'D', 'A', 'D', 'A', 'D', 'G', 'Em', 'D', 'A', 'D', 'A', 'G', 'D', 'G', 'D', 'A', 'D'  
X:1
L:1/8
M:4/4
K:D
"D" D2 FD A,DFA | dcde fdAF |"G" G2 BG"D" FADF |"A" (3GFE FD CE A,2 |"D" D2 FD A,DFA | dcde fdAF | 
"G" GABG"D" FADF |"A" EA,CE"D" D4 ::"A" A,B,CD EFGE |"D" FDEF"G" GABc | dBBA"Em" Bcde | 
"D" fdgf"A" e4 |"D" d2 fd"A" ceAc |"G" dcdB"D" AFDF |"G" G2 BG"D" FADF |"A" EA,CE"D" D4 :|  