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
{/G} E{/F} E F G- | G G B B | c2 c c | c d c2 ||{/B} c c !turn!c2 | B B !turn!G2 | G2 B B | %7
 c B !turn!G2 ||{/G} E F G B | c B !turn!G2 | G2 E F | E E !turn!C2 || %12  