Generate a piece of music.  
X:1
T:Music21 Fragment
C:Music21
L:1/4
M:none
I:linebreak $
K:none
V:1 treble 
V:1
 z z z z | z z z z | z z z z | z z z C ||{/G} F E2 C | B,2 G,2- | G,2 B,2 | C2 !turn!F2 || %8
{/D} E2 C2 | B, C E F | G G B B | c c c c ||{/c} B{/A} B ^F G | G G E =F | E E E/ F/ G/ A/ | %15
 F E D/ C/ C || %16  