Write musical pieces that adapt to the predetermined chord shifts.
'D', 'A7', 'A7', 'D', 'D', 'A7', 'D'  
X:1
L:1/4
M:2/2
K:D
 A |:"D" d d c c | B B A A | z B2 A | F3 F | A A A A | A A G F |"A7" z A2 G |"A7" E3 A | c c B B | 
 A A G G | z A2 G | E E F G | A A A B | A G F E |1"D" D4- | D A B c :|2"D" D4- | D2 F G | 
"A7" A A A B | A G F E |"D" D4- | D |]  