Generate a piece of music. It is monophony.  
X:1
T:Music21 Fragment
C:Music21
L:1/8
Q:1/4=69
M:6/8
I:linebreak $
K:D
V:1 treble 
V:1
 A>^GA B/B/ z A | AAf d2 z/ A/ | AGF F>GF | E>FG F2 z/ A/ | ^G>F^G A>^GA | B2 B c>dc | c>Bc ed>B | %7
 AB>^G !fermata!A2 z/ A/ | d2 A/A/ A>=GF | GAG F2 F | EEF AG>E | D!fermata!dB A2 G | %12
 FFG/A/ B/B/ z A | A^GA f2 f/e/ | dcB A>=GF | E2 G/>F/ D3 || %16  