Compose a musical masterpiece that mirrors Bach's signature sound and structure.  
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 treble 
%%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 c | c c c d | !fermata!e2 z e | e g c/d/ e | d2 !fermata!c e | d e c d | !fermata!B2 z c | %7
 c c d c | B2 !fermata!A B | B B B c | !fermata!d2 z d | d e f f | !fermata!e2 z e | e g f e | %14
 !fermata!d2 z d | e d c B | !fermata!A3 z |] %17
V:2
 z3 A | G A G A/B/ | !fermata!c2 z c | c c/B/ A/B/ c | c B !fermata!G c | B B3/2 A B/ | %6
 !fermata!^G2 z A | A G A/^G/ A | A ^G !fermata!E =G | G A G ^F | !fermata!G2 z B | B c c B | %12
 !fermata!c2 z c | c c3/2 B/ c | !fermata!B2 z B | B/A/ B3/2 A ^G/ | !fermata!E3 z |] %17
V:3
 z3 E | E/D/ C/D/ E F | !fermata!G2 z G | A G F G | G/D/ G/F/ !fermata!E G | G ^G E F | %6
 !fermata!E2 z E | F C F ^F | B,/ E D/ !fermata!C E | E ^F3/2 E/ =D/C/ | !fermata!B,2 z G | %11
 G G A G | !fermata!G2 z G | A G A/G/ G | !fermata!G2 z G/F/ | E3 E/>D/ | !fermata!C3 z |] %17
V:4
 z3"Am" A, |"C/E" E,"F" F,"C/E" E,"Dm" D, |"C" !fermata!C,2 z"C" C/B,/ | %3
"Am" A,"C/E" E,"F" F,"C/E" E,/F,/ |"Gsus4" G,2"C" !fermata!C,"C" C | %5
"G" G,/F,/"E" E,"Am" A,"Dm" D, |"E" !fermata!E,2 z"Am" A,/G,/ | %7
"F" F,/G,/"Fsus2" F,/E,/"Dm" D,"D#dim7" ^D, |"Esus4" E,2"Am" !fermata!A,"Em" E,/^F,/ | %9
"Em/G" G,"B7/D#" ^D,"Em" E,"D7/A" A, |"G" !fermata!G,2 z"G" G, |"G" G/=F/"C/E" E"Dm7" D"G" G, | %12
"C" !fermata!C2 z"C" C/B,/ |"Am" A,/G,/"Fsus2" F,/E,/"Dm7" D,"C" C, |"G" !fermata!G,2 z"G" G, | %15
"E/G#" ^G,/^F,/"E7/G#" G,/E,/"Am" A,"Esus4" E, |"Am" !fermata!A,,3 z |] %17  