Create a melodic piece that emulates Bach's compositional style.  
X:1
T:Music21 Fragment
T:Music21 Fragment
T:Music21
C:Music21
%%score 1 2 3 4
L:1/4
M:4/4
K:C
V:1 treble 
%%MIDI program 0
%%MIDI control 7 100
%%MIDI control 10 64
V:2 treble 
%%MIDI program 0
%%MIDI control 7 100
%%MIDI control 10 64
V:3 bass 
%%MIDI program 0
%%MIDI control 7 100
%%MIDI control 10 64
V:4 bass 
%%MIDI program 0
%%MIDI control 7 100
%%MIDI control 10 64
V:1
 z3 A | A A G A | F E !fermata!D A/B/ | c d A B | c B !fermata!A A | A A G A | %6
 F E !fermata!D A/B/ | c d A B | c B !fermata!A c | c c/_B/ A/G/ F/G/ | A G !fermata!F A | %11
 A A G F/E/ | E2 !fermata!D A | A G A =B | c/B/ A !fermata!G d | e d A/B/ c | B A B2 | %17
 !fermata!A3 z |] %18
V:2
 z3 E | F F F E | E/ D ^C/ D F | E D/E/ F F | E D ^C E | F F F E | E/ D ^C/ D F | E D/E/ F F | %8
 E D ^C A | G/F/ E/D/ C D/E/ | F E F C/D/ | E D D D | D ^C D E | F3/2 E/ F/A/ G/F/ | E/D/ C B, G | %15
 G F/E/ D E | E/D/ C F E/D/ | ^C3 z |] %18
V:3
 z3 A, | D D D A, | A,3/2 G,/ F, D | C/B,/ A, D D | ^G,/ A, G,/ A, A, | D D D A, | A,3/2 G,/ F, D | %7
 C/B,/ A, D D | ^G,/ A, G,/ A, E | C G, A, A,/_B,/ | C3/2 _B,/ A, A, | A,/G,/ F, G,/A,/ _B, | %12
 A,3/2 G,/ F, A, | D/=C/ _B, C D | G,3/2 ^F,/ G, B, | C/B,/ A,/^G,/ A, A, | ^G, A,2 G, | A,3 z |] %18
V:4
 z3"A/C#" ^C, |"Dm" D,/E,/"Dm/F" F,"G7/B" B,,"A/C#" ^C, | %2
"Dm" D,"Asus4" A,,"Dm" !fermata!D,"Dm" D, |"Am" A,/G,/"Dm/F" F,/E,/"Dm" D,/C,/"Bdim" B,,/A,,/ | %4
"C+/E" E,2"A" !fermata!A,,"A/C#" ^C, |"Dm" D,/E,/"Dm/F" F,"G7/B" B,,"A/C#" ^C, | %6
"Dm" D,"Asus4" A,,"Dm" !fermata!D,"Dm" D, |"Am" A,/G,/"Dm/F" F,/E,/"Dm" D,/C,/"Bdim" B,,/A,,/ | %8
"C+/E" E,2"A" !fermata!A,,"Am" A, |"C/E" E,/D,/"C" C,"F" F,/E,/"Em7b5/D" D, | %10
"F/A" A,,/_B,,/"C" C,"F" !fermata!F,,"F" F, |"A/C#" ^C,"Dm" D,/=C,/"Gm/Bb" _B,,/A,,/"Gm7" G,, | %12
"Asus4" A,,2"Dm" !fermata!D,"A/C#" ^C, |"Dm" D,"Gm" G,"F" F,/E,/"G/D" D, | %14
"C" C,"D7" D,"G" !fermata!G,,"G" G, |"C" C,"Dm" D,/E,/"Dm/F" F,"Am/C" C,/D,/ | %16
"E" E,"F" F,/E,/"Bm7b5/D" D,"E" E, |"A" !fermata!A,,3 z |] %18  