Develop a tune that showcases the foundational aspects of Bach's music.  
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 nm="Piano" snm="Pno"
%%MIDI program 0
%%MIDI control 7 100
%%MIDI control 10 64
V:2 treble nm="Piano" snm="Pno"
%%MIDI channel 3
%%MIDI program 0
%%MIDI control 7 100
%%MIDI control 10 64
V:3 bass nm="Piano" snm="Pno"
%%MIDI channel 4
%%MIDI program 0
%%MIDI control 7 100
%%MIDI control 10 64
L:1/8
V:4 bass nm="Piano" snm="Pno"
%%MIDI channel 5
%%MIDI program 0
%%MIDI control 7 100
%%MIDI control 10 64
L:1/8
V:1
 G G A A | B B/c/4d/4 !fermata!c2 | d d c c | B A/B/4c/4 A2 | !fermata!G2 G G | A A G F/E/ | %6
 !fermata!E2 G G | F F E D/E/4F/4 | D2 !fermata!C2 | G G A A | B B/c/4d/4 !fermata!c2 | %11
 G G/A/4_B/4 A/G/ =F/E/ | D/E/4F/4 D !fermata!C2 |] %13
V:2
 E E C F | F/E/ F !fermata!E2 | G G/F/ E3/2 ^F/ | G/^F/ E/C/ D3/2 C/ | !fermata!B,2 C C | %5
 C F F/E/ D | !fermata!^C2 C/D/ E/C/ | A, D/B,/ C C | C B, !fermata!G,2 | E E F F/E/ | %10
 D E !fermata!E2 | C C C/B,/ C | C B, !fermata!G,2 |] %13
V:3
 C2 C2 A,2 D2 | DC DB, !fermata!G,4 | B,C DB, B,A,/^G,/ A,2 | G,2 G,2 G,E, ^F,2 | %4
 !fermata!D,4 E,=F, G,E, | F,G, A,2 D,E, F,G, | !fermata!A,4 G,F, E,2 | F,2 G,2 G,2 A,F, | %8
 G,E, F,2 !fermata!E,4 | C2 C2 C2 D2 | ^G,A, B,G, !fermata!A,4 | E,2 E,2 F,D, C,G, | %12
 A,2 G,F, !fermata!E,4 |] %13
V:4
"C" C,D,"C/E" E,C,"F" F,E,"Dm/F" F,D, |"G7" G,2"G7" G,,2"C" !fermata!C,4 | %2
"G" G,,A,,"G/B" B,,G,,"Am/B" A,,B,,"Am/C" C,D, |"Em" E,D,"Am7/C" C,A,,"Dsus4" D,2"D" D,,2 | %4
"G" !fermata!G,,4"C" C,D,"C/E" E,C, |"F" F,E,"Dm" D,C,"G7/B" B,,^C,"Dm" D,2 | %6
"A" !fermata!A,,4"C#dim/E" E,D,"C#dim" ^C,A,, |"Dm" D,=C,"G7/B" B,,G,,"C" C,E,"Dm7/F" F,D, | %8
"Gsus4" G,2"G7" G,,2"C" !fermata!C,4 |"C" C_B,"Am7" A,G,"F" F,E,"Dm" D,C, | %10
"G#dim/B" B,,A,,"E/G#" ^G,,E,,"Am" !fermata!A,,4 |"C" C,_B,,"Am7" A,,G,,"F" F,,G,,"F/A" A,,G,, | %12
"Dm7/F" F,,2"G" G,,2"C" !fermata!C,4 |] %13  