Construct a piece of music that reflects the essence of Bach's 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 E/F/ | G A G F/E/ | !fermata!E2 z G | A B c c/B/ | B2 !fermata!A E/=F/ | G A G F/E/ | %6
 !fermata!E2 z G | A B c c/B/ | B2 !fermata!A d/c/ | B c/B/ A3/2 G/ | !fermata!G3 G | A B c3/2 c/ | %12
 !fermata!B3 G | G A G F/E/ | !fermata!E2 z G | A/B/ c c B | !fermata!c3 z |] %17
V:2
 z3 C/B,/ | C C C/B,/4A,/4 B, | !fermata!C2 z E | ^F ^G A E | E3/2 D/ !fermata!C C/B,/ | %5
 C C C/B,/4A,/4 B, | !fermata!C2 z E | ^F ^G A E | E3/2 D/ !fermata!C D | D E E/C/ D | %10
 !fermata!D3 D | D/E/ ^F G D | !fermata!D3 D | E F/E/ D D | !fermata!C2 z C | C D D/E/ F | %16
 !fermata!E3 z |] %17
V:3
 z3 G, | G, F, E,/D,/ G, | !fermata!G,2 z G, | D D E A, | A, ^G, !fermata!A, =G, | %5
 G, F, E,/D,/ G, | !fermata!G,2 z G, | D D E A, | A, ^G, !fermata!A, A, | G, G, G, ^F, | %10
 !fermata!B,3 B, | A, D C/B,/ A, | !fermata!G,3 B, | C F, G,/A,/ B, | !fermata!A,2 z G, | %15
 F,/G,/ A, G, G, | !fermata!G,3 z |] %17
V:4
 z3"C" C,/D,/ |"C/E" E,"F" F,"C/E" G,"G" G,, |"C" !fermata!C,2 z"C" C, | %3
"D7/C" C,"G#dim/B" B,,"Am" A,,/B,,/"Am/C" C,/D,/ |"Esus4" E,2"Am" !fermata!A,,"C" C,/D,/ | %5
"C/E" E,"F" F,"C/E" G,"G" G,, |"C" !fermata!C,2 z"C" C, | %7
"D7/C" C,"G#dim/B" B,,"Am" A,,/B,,/"Am/C" C,/D,/ |"Esus4" E,2"Am" !fermata!A,,"D/F#" ^F, | %9
"G" G,/^F,/"C/E" E,/D,/"Am7/C" C,/A,,/"D" D, |"G" !fermata!G,,3"G" G, | %11
"D/F#" ^F,"Bm/D" D,"C/E" E,"Dm7/F" =F, |"G" !fermata!G,3"G7/F" =F, | %13
"C/E" E,"Dm" D,/C,/"G/B" B,,"G7" G,, |"Am" !fermata!A,,2 z"C/E" E, | %15
"F" F,"D7/F#" ^F,"Gsus4" G,"G" G,, |"C" !fermata!C,3 z |] %17  