Generate a piece of music. It is monophony.  
X:1
T:Music21 Fragment
C:Music21
L:1/8
Q:1/4=98
M:4/4
I:linebreak $
K:C
V:1 treble 
V:1
 EF G2 EF G2 | E>F GA D2 z F | E>F GG AB cc | B>c d>B c3 z | E>F GG EF GG | E>F GA D2 z F | %6
 EF G>G AB !fermata!cc | B>c !fermata!d>B c3 z | e2 cc c2 AA | G<E E>C D2 z F | EF G2 AB c z/ c/ | %11
 Bc d>B c3 z | e2 d/e/4d/4c d2 cA | G<E D>C D2 z F | EF G2 AB !fermata!c z/ c/ | %15
 Bc !fermata!d>B c4 || %16  