Code:

#include <Audio.h>
#include <Wire.h>
#include <SPI.h>
#include <SD.h>
#include <SerialFlash.h>
// GUItool: begin automatically generated code
AudioSynthWaveform waveform2; //xy=64,56
AudioSynthWaveform waveform3; //xy=64,92
AudioSynthWaveform waveform4; //xy=64,125
AudioSynthWaveform waveform6; //xy=64,203
AudioSynthWaveform waveform7; //xy=64,239
AudioSynthWaveform waveform1; //xy=65,20
AudioSynthWaveform waveform8; //xy=64,272
AudioSynthWaveform waveform5; //xy=65,167
AudioSynthWaveform waveform10; //xy=68,348
AudioSynthWaveform waveform11; //xy=68,384
AudioSynthWaveform waveform12; //xy=68,417
AudioSynthWaveform waveform14; //xy=68,494
AudioSynthWaveform waveform15; //xy=68,530
AudioSynthWaveform waveform9; //xy=69,312
AudioSynthWaveform waveform16; //xy=68,563
AudioSynthWaveform waveform13; //xy=69,458
AudioMixer4 mixer1; //xy=194,70
AudioMixer4 mixer2; //xy=194,217
AudioMixer4 mixer3; //xy=198,362
AudioMixer4 mixer4; //xy=198,508
AudioMixer4 mixer5; //xy=376,294
AudioSynthWaveform waveform18; //xy=384,388
AudioSynthWaveform waveform19; //xy=384,424
AudioSynthWaveform waveform20; //xy=384,457
AudioSynthWaveform waveform22; //xy=384,535
AudioSynthWaveform waveform23; //xy=384,571
AudioSynthWaveform waveform17; //xy=385,352
AudioSynthWaveform waveform24; //xy=384,604
AudioSynthWaveform waveform21; //xy=385,499
AudioSynthWaveform waveform26; //xy=388,680
AudioSynthWaveform waveform27; //xy=388,716
AudioSynthWaveform waveform28; //xy=388,749
AudioSynthWaveform waveform30; //xy=388,826
AudioSynthWaveform waveform31; //xy=388,862
AudioSynthWaveform waveform25; //xy=389,644
AudioSynthWaveform waveform32; //xy=388,895
AudioSynthWaveform waveform29; //xy=389,790
AudioMixer4 mixer6; //xy=514,402
AudioMixer4 mixer7; //xy=514,549
AudioMixer4 mixer8; //xy=518,694
AudioMixer4 mixer9; //xy=518,840
AudioMixer4 mixer_a; //xy=696,626
AudioSynthWaveform waveform34; //xy=701,718
AudioSynthWaveform waveform35; //xy=701,754
AudioSynthWaveform waveform36; //xy=701,787
AudioSynthWaveform waveform38; //xy=701,865
AudioSynthWaveform waveform39; //xy=701,901
AudioMixer4 mixer_out; //xy=704,158
AudioSynthWaveform waveform33; //xy=702,682
AudioSynthWaveform waveform40; //xy=701,934
AudioSynthWaveform waveform37; //xy=702,829
AudioSynthWaveform waveform42; //xy=705,1010
AudioSynthWaveform waveform43; //xy=705,1046
AudioSynthWaveform waveform44; //xy=705,1079
AudioSynthWaveform waveform46; //xy=705,1156
AudioSynthWaveform waveform47; //xy=705,1192
AudioSynthWaveform waveform41; //xy=706,974
AudioSynthWaveform waveform48; //xy=705,1225
AudioSynthWaveform waveform45; //xy=706,1120
AudioMixer4 mixer10; //xy=831,732
AudioMixer4 mixer11; //xy=831,879
AudioMixer4 mixer12; //xy=835,1024
AudioMixer4 mixer13; //xy=835,1170
AudioOutputI2S i2s1; //xy=864,158
AudioMixer4 mixer14; //xy=1013,956
AudioSynthWaveform waveform50; //xy=1013,1051
AudioSynthWaveform waveform51; //xy=1013,1087
AudioSynthWaveform waveform52; //xy=1013,1120
AudioSynthWaveform waveform54; //xy=1013,1198
AudioSynthWaveform waveform55; //xy=1013,1234
AudioSynthWaveform waveform49; //xy=1014,1015
AudioSynthWaveform waveform56; //xy=1013,1267
AudioSynthWaveform waveform53; //xy=1014,1162
AudioSynthWaveform waveform58; //xy=1017,1343
AudioSynthWaveform waveform59; //xy=1017,1379
AudioSynthWaveform waveform60; //xy=1017,1412
AudioSynthWaveform waveform62; //xy=1017,1489
AudioSynthWaveform waveform63; //xy=1017,1525
AudioSynthWaveform waveform57; //xy=1018,1307
AudioSynthWaveform waveform64; //xy=1017,1558
AudioSynthWaveform waveform61; //xy=1018,1453
AudioMixer4 mixer15; //xy=1143,1065
AudioMixer4 mixer16; //xy=1143,1212
AudioMixer4 mixer17; //xy=1147,1357
AudioMixer4 mixer18; //xy=1147,1503
AudioMixer4 mixer19; //xy=1325,1289
AudioConnection patchCord1(waveform2, 0, mixer1, 1);
AudioConnection patchCord2(waveform3, 0, mixer1, 2);
AudioConnection patchCord3(waveform4, 0, mixer1, 3);
AudioConnection patchCord4(waveform6, 0, mixer2, 1);
AudioConnection patchCord5(waveform7, 0, mixer2, 2);
AudioConnection patchCord6(waveform1, 0, mixer1, 0);
AudioConnection patchCord7(waveform8, 0, mixer2, 3);
AudioConnection patchCord8(waveform5, 0, mixer2, 0);
AudioConnection patchCord9(waveform10, 0, mixer3, 1);
AudioConnection patchCord10(waveform11, 0, mixer3, 2);
AudioConnection patchCord11(waveform12, 0, mixer3, 3);
AudioConnection patchCord12(waveform14, 0, mixer4, 1);
AudioConnection patchCord13(waveform15, 0, mixer4, 2);
AudioConnection patchCord14(waveform9, 0, mixer3, 0);
AudioConnection patchCord15(waveform16, 0, mixer4, 3);
AudioConnection patchCord16(waveform13, 0, mixer4, 0);
AudioConnection patchCord17(mixer1, 0, mixer5, 0);
AudioConnection patchCord18(mixer2, 0, mixer5, 1);
AudioConnection patchCord19(mixer3, 0, mixer5, 2);
AudioConnection patchCord20(mixer4, 0, mixer5, 3);
AudioConnection patchCord21(mixer5, 0, mixer_out, 0);
AudioConnection patchCord22(waveform18, 0, mixer6, 1);
AudioConnection patchCord23(waveform19, 0, mixer6, 2);
AudioConnection patchCord24(waveform20, 0, mixer6, 3);
AudioConnection patchCord25(waveform22, 0, mixer7, 1);
AudioConnection patchCord26(waveform23, 0, mixer7, 2);
AudioConnection patchCord27(waveform17, 0, mixer6, 0);
AudioConnection patchCord28(waveform24, 0, mixer7, 3);
AudioConnection patchCord29(waveform21, 0, mixer7, 0);
AudioConnection patchCord30(waveform26, 0, mixer8, 1);
AudioConnection patchCord31(waveform27, 0, mixer8, 2);
AudioConnection patchCord32(waveform28, 0, mixer8, 3);
AudioConnection patchCord33(waveform30, 0, mixer9, 1);
AudioConnection patchCord34(waveform31, 0, mixer9, 2);
AudioConnection patchCord35(waveform25, 0, mixer8, 0);
AudioConnection patchCord36(waveform32, 0, mixer9, 3);
AudioConnection patchCord37(waveform29, 0, mixer9, 0);
AudioConnection patchCord38(mixer6, 0, mixer_a, 0);
AudioConnection patchCord39(mixer7, 0, mixer_a, 1);
AudioConnection patchCord40(mixer8, 0, mixer_a, 2);
AudioConnection patchCord41(mixer9, 0, mixer_a, 3);
AudioConnection patchCord42(mixer_a, 0, mixer_out, 1);
AudioConnection patchCord43(waveform34, 0, mixer10, 1);
AudioConnection patchCord44(waveform35, 0, mixer10, 2);
AudioConnection patchCord45(waveform36, 0, mixer10, 3);
AudioConnection patchCord46(waveform38, 0, mixer11, 1);
AudioConnection patchCord47(waveform39, 0, mixer11, 2);
AudioConnection patchCord48(mixer_out, 0, i2s1, 0);
AudioConnection patchCord49(mixer_out, 0, i2s1, 1);
AudioConnection patchCord50(waveform33, 0, mixer10, 0);
AudioConnection patchCord51(waveform40, 0, mixer11, 3);
AudioConnection patchCord52(waveform37, 0, mixer11, 0);
AudioConnection patchCord53(waveform42, 0, mixer12, 1);
AudioConnection patchCord54(waveform43, 0, mixer12, 2);
AudioConnection patchCord55(waveform44, 0, mixer12, 3);
AudioConnection patchCord56(waveform46, 0, mixer13, 1);
AudioConnection patchCord57(waveform47, 0, mixer13, 2);
AudioConnection patchCord58(waveform41, 0, mixer12, 0);
AudioConnection patchCord59(waveform48, 0, mixer13, 3);
AudioConnection patchCord60(waveform45, 0, mixer13, 0);
AudioConnection patchCord61(mixer10, 0, mixer14, 0);
AudioConnection patchCord62(mixer11, 0, mixer14, 1);
AudioConnection patchCord63(mixer12, 0, mixer14, 2);
AudioConnection patchCord64(mixer13, 0, mixer14, 3);
AudioConnection patchCord65(mixer14, 0, mixer_out, 2);
AudioConnection patchCord66(waveform50, 0, mixer15, 1);
AudioConnection patchCord67(waveform51, 0, mixer15, 2);
AudioConnection patchCord68(waveform52, 0, mixer15, 3);
AudioConnection patchCord69(waveform54, 0, mixer16, 1);
AudioConnection patchCord70(waveform55, 0, mixer16, 2);
AudioConnection patchCord71(waveform49, 0, mixer15, 0);
AudioConnection patchCord72(waveform56, 0, mixer16, 3);
AudioConnection patchCord73(waveform53, 0, mixer16, 0);
AudioConnection patchCord74(waveform58, 0, mixer17, 1);
AudioConnection patchCord75(waveform59, 0, mixer17, 2);
AudioConnection patchCord76(waveform60, 0, mixer17, 3);
AudioConnection patchCord77(waveform62, 0, mixer18, 1);
AudioConnection patchCord78(waveform63, 0, mixer18, 2);
AudioConnection patchCord79(waveform57, 0, mixer17, 0);
AudioConnection patchCord80(waveform64, 0, mixer18, 3);
AudioConnection patchCord81(waveform61, 0, mixer18, 0);
AudioConnection patchCord82(mixer15, 0, mixer19, 0);
AudioConnection patchCord83(mixer16, 0, mixer19, 1);
AudioConnection patchCord84(mixer17, 0, mixer19, 2);
AudioConnection patchCord85(mixer18, 0, mixer19, 3);
AudioConnection patchCord86(mixer19, 0, mixer_out, 3);
AudioControlSGTL5000 sgtl5000_1; //xy=822,276
// GUItool: end automatically generated code
void setup()
{
}
void loop()
{
}

I've included a blank sketch instantiating such a scheme. You can just copy the code and import it into the design tool to see what I mean.