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
{/^F} G G G2 | B2 B B | c c c2 | c d c c ||{/G} c2 !turn!c2 | B B G2 | G G B c | B2 G2 || %8
{/C} B, C E F | G G B c | c/ c/ e/ d/ c/ B/ A/ G/ | F/ G/ F/ E/ D/ C/ E/ F/ || %12
{/F} B A/ B/ !turn!G2 | z z z z | z z z z | z z z z || %16  