Develop a piece of music that mirrors the essence of Bach's noteworthy achievements.  
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
L:1/8
V:4 bass 
%%MIDI program 0
%%MIDI control 7 100
%%MIDI control 10 64
L:1/8
V:1
 z3 G | G G G G | G/A/ B !fermata!c c | d d c G | G/A/ B !fermata!c c | d d c G | %6
 A G !fermata!F G | A B !fermata!c2 | _B/A/ G/A/ !fermata!B A | G G !fermata!G2 |] %10
V:2
 z3 D | E F E E | D3/2 E/4F/4 !fermata!E F/G/ | A/G/ F F3/2 E/ | D G/F/ !fermata!E F | F F F E | %6
 E/F/ E !fermata!D E | F F/E/ !fermata!E2 | ^F G/D/ !fermata!D =F | F E !fermata!D2 |] %10
V:3
 z6 B,2 | C2 D2 D2 C2 | B,A, G,2 !fermata!G,2 A,C | F2 A,B, C2 C2 | B,A, G,2 !fermata!G,2 A,2 | %5
 A,2 D2 G,2 C_B, | A,2 _B,A, !fermata!A,2 C2 | CD D2 !fermata!C4 | DC _B,A, !fermata!G,2 A,2 | %9
 D3 C C=B,/A,/ !fermata!B,2 |] %10
V:4
 z6"G" G,F, |"C/E" E,D,"G7/B" C,B,,"C" C,D,"C/E" E,F, |"G" G,2"G" G,,2"C" !fermata!C,2"F" F,E, | %3
"Dm" D,E,"Dm/F" F,G,"F/A" A,B,"Csus4" C2 |"G" G,F,"Em" E,D,"C" !fermata!C,2"F" F,E, | %5
"Dm" D, C,2 B,,"Csus4" C,D,"C/E" E,D, |"A7/C#" ^C, D,2 C,"Dm" !fermata!D,2"C" =C,B,, | %7
"Bm7b5/A" A,, A,2 ^G,"Am" !fermata!A,4 |"Bb+/D" D,2"Edim" E,^F,"Gm" !fermata!G,2"Dm" D,C, | %9
"G7/B" =B,,G,,"C" C,2"Gsus4" !fermata!G,,4 |] %10  