diff --git a/05Wavetable/05Wavetable.ino b/05Wavetable/05Wavetable.ino
index b7a78e0..c8e684f 100644
--- a/05Wavetable/05Wavetable.ino
+++ b/05Wavetable/05Wavetable.ino
@@ -92,7 +92,7 @@ void setwave(){
     int val=0;
 
     //saw
-    val = dacmax * isamp / nsamp;
+    //val = dacmax * isamp / nsamp;
     //val = ( isamp < nsamp / 2 ) ? 0 : dacmax - 1;
         //sine
     //val=(sin(phi)+1.0)*dacmax/2;
diff --git a/12SequencerII/12SequencerII.ino b/12SequencerII/12SequencerII.ino
index 461c38b..fe96bfe 100644
--- a/12SequencerII/12SequencerII.ino
+++ b/12SequencerII/12SequencerII.ino
@@ -41,7 +41,7 @@ void setup() {
   // set compare match register for 1hz increments
   //OCR1A = 15624;// = (16*10^6) / (1*1024) - 1 (must be <65536)
   //OCR1A = 7812;// = (16*10^6) / (1*1024) - 1 (must be <65536)
-  OCR1A = 800;
+  OCR1A = 2196;  // about 135bpm?
   // turn on CTC mode
   TCCR1B |= (1 << WGM12);
   // Set CS10 and CS12 bits for 1024 escaler
@@ -63,7 +63,6 @@ void setup() {
   mcp.setSpeed(800000L);
   make_tuning(12);
   note=0;
-  Serial.println("hello");
 }
 
 void make_tuning(int edo) {
diff --git a/21FMSynth/21FMSynth.ino b/21FMSynth/21FMSynth.ino
new file mode 100644
index 0000000..a67fe25
--- /dev/null
+++ b/21FMSynth/21FMSynth.ino
@@ -0,0 +1,126 @@
+//waveform generator
+
+// hacked from https://www.instructables.com/Arduino-Waveform-Generator-1/
+
+#include <Adafruit_MCP4728.h>
+#include <Wire.h>
+
+Adafruit_MCP4728 mcp;
+
+#define nsamp 32
+#define dacmax 256
+
+const byte nclk = 200; // a guess
+long int freq; //frequency in Hz
+long unsigned int phase;
+long unsigned int phase_inc;
+
+int note = 0;
+int gate;
+int decay = 128;
+
+float pattern[16];
+
+long unsigned int pattern_inc[4];
+
+void setup() {
+  TIMSK0 &= ~_BV(TOIE0); // disable timer0 overflow interrupt
+
+  cli();
+
+//set timer1 interrupt at 1Hz
+  TCCR1A = 0;// set entire TCCR1A register to 0
+  TCCR1B = 0;// same for TCCR1B
+  TCNT1  = 0;//initialize counter value to 0
+  // set compare match register for 1hz increments
+  OCR1A = 3905;// = (16*10^6) / (1*1024) - 1 (must be <65536)
+  // turn on CTC mode
+  TCCR1B |= (1 << WGM12);
+  // Set CS10 and CS12 bits for 1024 prescaler
+  TCCR1B |= (1 << CS12) | (1 << CS10);  
+  // enable timer compare interrupt
+  TIMSK1 |= (1 << OCIE1A);
+
+  sei();
+
+
+  Serial.begin(115200);
+
+  if (!mcp.begin(0x64)) {
+    while (1) {
+      delay(100);
+    }
+  }
+
+//  mcp.setSpeed(400000L);
+//  mcp.setSpeed(800000L);
+  mcp.setSpeed(800000L);
+
+  freq=440;
+  phase=0;
+  //pattern[0] = 220.0;
+  // pattern[1] = 261.6255653005987;
+  // pattern[2] = 369.9944227116345;
+  // pattern[3] = 391.9954359817495;
+  for( int i = 0; i < 16; i++ ) {
+    pattern[i] = 440 + i * 80;
+  }
+
+  pattern[1] = 0;
+  pattern[2] = 0;
+
+  pattern[4] = 0;
+  pattern[5] = 0;
+ 
+
+  for( int i = 0; i < 16; i++ ) {
+    pattern_inc[i] = pattern[i] * 975592.231884058;
+  }
+
+  setwave();
+}
+
+const float pi=3.14159265;
+byte waveform[nsamp];
+byte phaseb = 0;
+void setwave(){
+  for (int isamp=0; isamp<nsamp; ++isamp){
+    float phip=(isamp+0.5)/nsamp;
+    float phi=2*pi*phip;
+    int val=0;
+
+    //saw
+    //val = dacmax * isamp / nsamp;
+    //val = ( isamp < nsamp / 2 ) ? 0 : dacmax - 1;
+        //sine
+    val=(sin(phi)+1.0)*dacmax/2;
+    //val=((sin(phi)+0.333*sin(3*phi))/0.943+1)*dacmax/2;
+
+    val=max(val,0);
+    val=min(val,dacmax-1);
+    waveform[isamp]=val;
+  }
+}
+
+
+
+ISR(TIMER1_COMPA_vect){
+  note += 1;
+  if( note > 15 ) {
+    note = 0;
+  }
+  phase_inc = pattern_inc[note];
+  gate = 4095;
+}
+ 
+
+
+void loop() {
+  phase += phase_inc;
+  int redphase = phase >> 27;
+  mcp.fastWrite(waveform[redphase] << 4, gate, 0, 0);
+  if( gate > 0 ) {
+    gate -= decay;
+  }
+}
+
diff --git a/22Envelopes/22Envelopes.ino b/22Envelopes/22Envelopes.ino
new file mode 100644
index 0000000..f1ecba1
--- /dev/null
+++ b/22Envelopes/22Envelopes.ino
@@ -0,0 +1,92 @@
+// Triggering shaped envelopes
+
+#include <Adafruit_MCP4728.h>
+#include <Wire.h>
+
+Adafruit_MCP4728 mcp;
+
+
+float tuning[37];
+float voltrange = 4.85;  // measured this, probably not accurate
+float octave = 4096.0 / voltrange; // number of DAC steps in an octave
+
+//bool gates[] = { true, false, true, false, true, false, false, true };
+
+bool gates[] = { true, false, false, false, true, false, false, false };
+
+
+int freqs[8];
+
+int lpattern = 8;
+int note = 0;
+
+bool trigger = false;
+long t0 = 0;
+
+
+void setup() {
+
+  cli();
+
+//set timer1 interrupt at 1Hz
+  TCCR1A = 0;// set entire TCCR1A register to 0
+  TCCR1B = 0;// same for TCCR1B
+  TCNT1  = 0;//initialize counter value to 0
+  // set compare match register for 1hz increments
+  //OCR1A = 15624;// = (16*10^6) / (1*1024) - 1 (must be <65536)
+  //OCR1A = 7812;// = (16*10^6) / (1*1024) - 1 (must be <65536)
+  OCR1A = 10000;
+  // turn on CTC mode
+  TCCR1B |= (1 << WGM12);
+  // Set CS10 and CS12 bits for 1024 escaler
+  TCCR1B |= (1 << CS12) | (1 << CS10);  
+  // enable timer compare interrupt
+  TIMSK1 |= (1 << OCIE1A);
+
+  sei();
+
+
+
+  if (!mcp.begin(0x64)) {
+    while (1) {
+      delay(100);
+    }
+  }
+
+  randomSeed(analogRead(A0));
+  mcp.setSpeed(800000L);
+
+  for( int i = 0; i < 8; i++ ) {
+    freqs[i] = random(10, 450);
+  }
+
+  trigger = true;
+}
+
+
+ISR(TIMER1_COMPA_vect){ // called once every note
+  trigger = true;
+}
+
+
+
+void loop() {
+  long now = millis();
+  float f1;
+  int gate;
+  long freq;
+  if( trigger ) {
+    t0 = now;
+    trigger = false;
+    freq = freqs[note];
+    gate = gates[note];
+    note++;
+    if( note == lpattern ) {
+      note = 0;
+    }
+  }
+  f1 = 0.5 - 0.5 * sin((float)(now - t0) / (float)1000.0);
+  mcp.setChannelValue(MCP4728_CHANNEL_A, round(4095.0 * f1));
+  mcp.setChannelValue(MCP4728_CHANNEL_B, gate ? 4095 : 0);
+}
+
diff --git a/23SequencerEnvelope/23SequencerEnvelope.ino b/23SequencerEnvelope/23SequencerEnvelope.ino
new file mode 100644
index 0000000..6461d5e
--- /dev/null
+++ b/23SequencerEnvelope/23SequencerEnvelope.ino
@@ -0,0 +1,167 @@
+// Better sequencer which uses interrupts
+
+#include <Adafruit_MCP4728.h>
+#include <Wire.h>
+
+Adafruit_MCP4728 mcp;
+
+
+float tuning[37];
+float voltrange = 4.85;  // measured this, probably not accurate
+float octave = 4096.0 / voltrange; // number of DAC steps in an octave
+
+
+int note = 0;
+
+// kick
+// int pitch[] = { 8, -1, -1, -1, 8,-1, -1, -1, 8,-1, -1, -1, 8, -1, -1, 8, 
+//                 8, -1, -1, -1, 8,-1, -1, -1, -1,-1, 8, -1, -1, 8, -1, 8,
+// };
+// float dur[] = { 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+// 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, };
+
+
+// hi hat
+// int pitch[] = { 8, 8, -1, 8, 8, 8, -1, 8, 8,8 , -1, 8, 8, 8, -1, 8, 
+//                 8, 8, -1, 8, 8, 8, -1, 8, 8,8 , -1, 8, 8, 8, 8, 8, 
+// };
+// float dur[] = { 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+// 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, };
+
+// bass triggers
+
+int pitch[] = { 1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, -1, -1, -1, 
+                1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, -1, -1, -1, };
+                
+float dur[] = { 8, 1, 1,1,  1,1,1,1,  1,1,1,1, 4, 1,1,1,
+8, 1, 1,1,  1,1,1,1,  1,1,1,1, 4, 1,1,1,};
+
+
+int phrase = 32;
+
+int s;
+int bpm = 110;
+int beat_m = 100; // fix me coordinate with timer code
+bool noteon = false;
+int beat = false;
+long notestart, notedur;
+
+
+void setup() {
+  Serial.begin(115200);
+
+  float freqint = 60.0 / (float)bpm;
+
+  int ocr = round(16 * 10 ^ 6 / (1024.0 * freqint * 16)) - 1
+
+  Serial.println(ocr);
+
+  if( ocr < 65536 ) {
+
+    cli();
+
+
+
+  //set timer1 interrupt at 1Hz
+    TCCR1A = 0;// set entire TCCR1A register to 0
+    TCCR1B = 0;// same for TCCR1B
+    TCNT1  = 0;//initialize counter value to 0
+    // set compare match register for 1hz increments
+    //OCR1A = 15624;// = (16*10^6) / (1*1024) - 1 (must be <65536)
+    //OCR1A = 7812;// = (16*10^6) / (1*1024) - 1 (must be <65536)
+    OCR1A = ocr; 
+    // turn on CTC mode
+    TCCR1B |= (1 << WGM12);
+    // Set CS10 and CS12 bits for 1024 escaler
+    TCCR1B |= (1 << CS12) | (1 << CS10);  
+    // enable timer compare interrupt
+    TIMSK1 |= (1 << OCIE1A);
+
+    sei();
+
+  } else {
+    Serial.println("BPM out of range")
+  }
+
+  if (!mcp.begin(0x64)) {
+    while (1) {
+      delay(100);
+    }
+  }
+
+  // randomSeed(analogRead(A0));
+  mcp.setSpeed(800000L);
+  make_tuning(7);
+  note=0;
+}
+
+void make_tuning(int edo) {
+  float n0 = 0;
+  float edof = (float)edo;
+  for( int i = 0; i < 37; i++ ) {
+      tuning[i] = round(n0 + octave * (float)i / edof);
+  }
+
+}
+
+float mod_f(int x) {
+  return 1 - sq((float)x / 1000.0);
+}
+
+
+
+ISR(TIMER1_COMPA_vect){ // called once every note
+  beat = true;
+}
+
+
+
+void loop() {
+  float mod;
+  int o;
+  long now = millis();
+  if( beat ) {
+    beat = false;
+    if( pitch[s] > -1 ) {
+      notestart = millis();
+      notedur = round(beat_m * dur[s]);
+      noteOn(pitch[s]);
+      noteon = true;
+    }
+    s += 1;
+    if( s == phrase ) {
+      s = 0;
+    }
+  } else {
+    if( noteon ) {
+        mod = mod_f(now - notestart);
+        o = round(mod * 4095.0);
+        if( o > 4095 ) {
+          o = 4095;
+        }
+        if( o < 0 ) {
+          o = 0;
+        } 
+        mcp.setChannelValue(MCP4728_CHANNEL_C, o);
+      if( now - notestart > notedur ) {
+        noteOff();
+        noteon = false;
+      }
+    }
+  }
+}
+
+
+void noteOn(int note) {
+  if( note > -1 ) {
+    mcp.setChannelValue(MCP4728_CHANNEL_A, tuning[note]);
+    mcp.setChannelValue(MCP4728_CHANNEL_B, 4095);
+  }
+}
+
+void noteOff() {
+    Serial.println("off");
+    mcp.setChannelValue(MCP4728_CHANNEL_B, 0);
+}
+
+
diff --git a/24SequencerBPM/24SequencerBPM.ino b/24SequencerBPM/24SequencerBPM.ino
new file mode 100644
index 0000000..cb2c1e8
--- /dev/null
+++ b/24SequencerBPM/24SequencerBPM.ino
@@ -0,0 +1,159 @@
+// Better sequencer which uses interrupts
+
+#include <Adafruit_MCP4728.h>
+#include <Wire.h>
+
+Adafruit_MCP4728 mcp;
+
+
+float tuning[37];
+float voltrange = 4.85;  // measured this, probably not accurate
+float octave = 4096.0 / voltrange; // number of DAC steps in an octave
+
+
+// melody
+// int pitch[] = { 1,3,7,2,3,4,3,4,3,4,6,7,3,4,3,1,3, 5, 9, 4, 5, 6, 5, 6, 5, 6, 8, 9, 5, 6, 5, 3};
+// float dur[] = { 0.1,0.00, 0.1, 0.05, 0.1,0.05, 0.05, 0.05,
+// 0.1,0.05, 0.1, 0.05, 0.1,0.05, 0.05, 0.05,
+// 0.1,0.05, 0.1, 0.05, 0.1,0.05, 0.05, 0.05,
+// 0.1,0.05, 0.1, 0.05, 0.1,0.05, 0.05, 0.05,};
+
+
+int pitch[] = { 4, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,  2, -1, -1, -1,
+-1, -1, -1, -1, -1, -1, -1, -1,-1, -1, -1, -1,-1, -1, -1, -1, };
+int dur[] = { 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  };
+
+int note = 0;
+int phrase = 32;
+
+int s;
+int bpm = 110;
+float beat_s = 60.0 / (float)bpm;
+float beat_m = 1000.0 * beat_s; 
+bool noteon = false;
+int beat = false;
+long notestart, notedur, barstart;
+
+
+void setup() {
+  Serial.begin(115200);
+
+  float freqint = 60.0 / (float)bpm;
+
+  int ocr = round(16000000.0 / (1024.0 * freqint * 16)) - 1;
+  Serial.println(ocr);
+  if( ocr < 65536 ) {
+
+    cli();
+
+    TCCR1A = 0;// set entire TCCR1A register to 0
+    TCCR1B = 0;// same for TCCR1B
+    TCNT1  = 0;//initialize counter value to 0
+    OCR1A = ocr; 
+    // turn on CTC mode
+    TCCR1B |= (1 << WGM12);
+    // Set CS10 and CS12 bits for 1024 escaler
+    TCCR1B |= (1 << CS12) | (1 << CS10);  
+    // enable timer compare interrupt
+    TIMSK1 |= (1 << OCIE1A);
+
+    sei();
+
+  } else {
+    Serial.println("BPM out of range");
+  }
+
+  if (!mcp.begin(0x64)) {
+    while (1) {
+      delay(100);
+    }
+  }
+
+  // randomSeed(analogRead(A0));
+  mcp.setSpeed(800000L);
+  make_tuning(7);
+  note=0;
+  barstart=millis();
+}
+
+void make_tuning(int edo) {
+  float n0 = 0;
+  float edof = (float)edo;
+  for( int i = 0; i < 37; i++ ) {
+      tuning[i] = round(n0 + octave * (float)i / edof);
+  }
+
+}
+
+
+// mod_note argument is milliseconds from the start of last note
+float mod_note(int x) {
+  return 1 - sq((float)x / 1000.0);
+}
+
+// mod_note argument is milliseconds from the start of this bar
+float mod_bar(int x) {
+  return 0.5 + 0.5 * sin((float)x / (beat_m * 2));
+}
+
+void set_mod(MCP4728_channel_t channel, float v) {
+  int o;
+  o = round(v * 4095.0);
+  if( o > 4095 ) {
+    o = 4095;
+  }
+  if( o < 0 ) {
+    o = 0;
+  } 
+  mcp.setChannelValue(channel, o);
+}
+
+ISR(TIMER1_COMPA_vect){ // called once every beat
+  beat = true;
+}
+
+
+void loop() {
+  float mod;
+  int o;
+  long now = millis();
+  if( beat ) {
+    beat = false;
+    if( pitch[s] > -1 ) {
+      notestart = millis();
+      notedur = round(beat_m * dur[s]);
+      noteOn(pitch[s]);
+      noteon = true;
+    }
+    s += 1;
+    if( s == phrase ) {
+      s = 0;
+      barstart = notestart;
+    }
+  } else {
+    if( noteon ) {
+        set_mod(MCP4728_CHANNEL_C, mod_note(now - notestart));
+      if( now - notestart > notedur ) {
+        noteOff();
+        noteon = false;
+      }
+    }
+    set_mod(MCP4728_CHANNEL_D, mod_bar(now - barstart));
+  }
+}
+
+
+void noteOn(int note) {
+  if( note > -1 ) {
+    mcp.setChannelValue(MCP4728_CHANNEL_A, tuning[note]);
+    mcp.setChannelValue(MCP4728_CHANNEL_B, 4095);
+  }
+}
+
+void noteOff() {
+    Serial.println("off");
+    mcp.setChannelValue(MCP4728_CHANNEL_B, 0);
+}
+
+
diff --git a/25EnvelopesII/25EnvelopesII.ino b/25EnvelopesII/25EnvelopesII.ino
new file mode 100644
index 0000000..6c7afd5
--- /dev/null
+++ b/25EnvelopesII/25EnvelopesII.ino
@@ -0,0 +1,160 @@
+// Better sequencer which uses interrupts
+
+#include <Adafruit_MCP4728.h>
+#include <Wire.h>
+
+Adafruit_MCP4728 mcp;
+
+
+float tuning[37];
+float voltrange = 4.85;  // measured this, probably not accurate
+float octave = 4096.0 / voltrange; // number of DAC steps in an octave
+
+
+// melody
+
+// int pitch[] = { 4, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+// -1, -1, -1, -1, -1, -1, -1, -1,-1, -1, -1, -1,2, -1, -1, -1, };
+// int dur[] = { 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+//             0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0,  };
+
+// hi hat
+
+int pitch[] = { 1, 2, 3,2, 4, 2,5, 0,1, 2, 3,2, 4, 2,5, 0,1, 2, 3,2, 4, 2,5, 0,1, 2, 3,2, 4, 2,5, 0, };
+int dur[] = { 0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,0.1,  };
+
+
+int note = 0;
+int phrase = 32;
+
+int s;
+int bpm = 80;
+float beat_s = 60.0 / (float)bpm;
+float beat_m = 1000.0 * beat_s; 
+bool noteon = false;
+int beat = false;
+long notestart, notedur, barstart;
+
+
+void setup() {
+  Serial.begin(115200);
+
+  float freqint = 60.0 / (float)bpm;
+
+  int ocr = round(16000000.0 / (1024.0 * freqint * 16)) - 1;
+  Serial.println(ocr);
+  if( ocr < 65536 ) {
+
+    cli();
+
+    TCCR1A = 0;// set entire TCCR1A register to 0
+    TCCR1B = 0;// same for TCCR1B
+    TCNT1  = 0;//initialize counter value to 0
+    OCR1A = ocr; 
+    // turn on CTC mode
+    TCCR1B |= (1 << WGM12);
+    // Set CS10 and CS12 bits for 1024 escaler
+    TCCR1B |= (1 << CS12) | (1 << CS10);  
+    // enable timer compare interrupt
+    TIMSK1 |= (1 << OCIE1A);
+
+    sei();
+
+  } else {
+    Serial.println("BPM out of range");
+  }
+
+  if (!mcp.begin(0x64)) {
+    while (1) {
+      delay(100);
+    }
+  }
+
+  // randomSeed(analogRead(A0));
+  mcp.setSpeed(800000L);
+  make_tuning(12);
+  note=0;
+  barstart=millis();
+}
+
+void make_tuning(int edo) {
+  float n0 = 0;
+  float edof = (float)edo;
+  for( int i = 0; i < 37; i++ ) {
+      tuning[i] = round(n0 + octave * (float)i / edof);
+  }
+
+}
+
+
+// mod_note argument is milliseconds from the start of last note
+float mod_note(int x) {
+  float xb = x / (0.2 * beat_m);
+  return 0.5 + 0.5 * xb * (xb - 1) * ( xb - 2);
+}
+
+// mod_note argument is milliseconds from the start of this bar
+float mod_bar(int x) {
+  return 0.5 + 0.5 * sin((float)x / (beat_m * 2));
+}
+
+void set_mod(MCP4728_channel_t channel, float v) {
+  int o;
+  o = round(v * 4095.0);
+  if( o > 4095 ) {
+    o = 4095;
+  }
+  if( o < 0 ) {
+    o = 0;
+  } 
+  mcp.setChannelValue(channel, o);
+}
+
+ISR(TIMER1_COMPA_vect){ // called once every beat
+  beat = true;
+}
+
+
+void loop() {
+  float mod;
+  int o;
+  long now = millis();
+  if( beat ) {
+    beat = false;
+    if( pitch[s] > -1 ) {
+      notestart = millis();
+      notedur = round(beat_m * dur[s]);
+      noteOn(pitch[s]);
+      noteon = true;
+    }
+    s += 1;
+    if( s == phrase ) {
+      s = 0;
+      barstart = notestart;
+    }
+  } else {
+    if( noteon ) {
+        set_mod(MCP4728_CHANNEL_C, mod_note(now - notestart));
+      if( now - notestart > notedur ) {
+        noteOff();
+        noteon = false;
+      }
+    }
+    set_mod(MCP4728_CHANNEL_D, mod_bar(now - barstart));
+  }
+}
+
+
+void noteOn(int note) {
+  if( note > -1 ) {
+    mcp.setChannelValue(MCP4728_CHANNEL_A, tuning[note]);
+    mcp.setChannelValue(MCP4728_CHANNEL_B, 4095);
+  }
+}
+
+void noteOff() {
+    Serial.println("off");
+    mcp.setChannelValue(MCP4728_CHANNEL_B, 0);
+}
+
+
diff --git a/README.md b/README.md
index 028fc94..bd8bb45 100644
--- a/README.md
+++ b/README.md
@@ -95,3 +95,9 @@ Using the random-note-clouds technique from the 8th but this time picking
 pitches from a hexany tuning, running it four times and drenching it in
 reverb
 
+### 20 Fibomod
+
+Using the Fibonacci series modulo n, also known as the (Pisano period)[https://en.wikipedia.org/wiki/Pisano_period], as a wavetable, and incrementing n for each note in the sequence
+
+
+