nyanpasu64/instructions.md

## instructions.md

      
    Raw
  

              instructions.md
            
          
    Just updated my N163 Waveform Generator with "full normalize" mode, to get a bit of extra amplitude out of your waves.


Scroll to n163-nyanpasu64.ny. Click "raw" and save it to %appdata%\audacity\Plug-Ins

Optionally, install my 60hz beat track generator. Save zz_beater.ny to the same folder.
To generate a beat track, click menu Generate/Beat Track... and specify how many beats. Mute the resulting track, collapse, and drag it above your sound sample.
Alternatively, menu Analyze/Regular Interval Labels...


Under Preferences (Ctrl+P), on the left click Keyboard. On the right, search N163, and Set to Shift+Enter.


Zoom into your audio.


To generate a waveform, first select one period of audio (pressing z will align your selection with zero crossings.)

Press Shift+Space to preview the note. Ensure it's approximately the right pitch.


For the first waveform, press Shift+Enter to generate a wave.


For subsequent waveforms, Shift+Down, Shift+Enter to append to the same label track.


Use the menu, Edit/Labels/Edit Labels, to export all N163 waveforms to a file, instead of copying from Audacity labels.


My fork of 0CC (https://github.com/nyanpasu64/0CC-FamiTracker/releases) supports pasting many N163 waves at the same time.

To copy all waveforms, open the file and delete everything but the last column. Add semicolons at the end of each line.
In the text editor, copy all lines. Then in the N163 instrument editor, click the Paste button to paste all waveforms sequentially.


## n163-nyanpasu64.ny
;nyquist plug-in
;version 3
;type analyze
;name "N163/FDS waveform..."
;action "Calculating N163/FDS waveform..."

;control mode "Mode" choice "Namco 163,Famicom Disk System" 0
;control wavesize-choice "Wave size (N163 only)" choice "4,8,12,16,20,24,28,32,36,40,44,48,52,56,60,64,68,72,76,80,84,88,92,96,100,104,108,112,116,120,124,128,132,136,140,144,148,152,156,160,164,168,172,176,180,184,188,192,196,200,204,208,212,216,220,224,228,232,236,240" 7
;control normalize-choice "Normalize result" choice "no,balanced,full" 2

; **********************************************************************
; Namco 163/Famicom Disk System waveform tool
; By Kef Schecter
; Public domain
; **********************************************************************

(setf *gc-flag* nil)

(setf mode-n163 0)
(setf mode-fds 1)

(setf normalize-no 0)
(setf normalize-balanced 1)
(setf normalize-full 2)

(cond
  ((= mode mode-n163) ; Convert from wavesize-choice table to actual
                      ; wave size (4, 8, 12...)
                      (setf wavesize (* 4 (1+ wavesize-choice)))
                      (setf max-volume 15))
  (t (setf wavesize 64)                         ; FDS mode
     (setf max-volume 63)))

(setf half-max-volume (/ (+ max-volume 1) 2.0))

(setf new-old-ratio (/ (float wavesize) len))

(setf resample-rate (truncate (* *sound-srate* new-old-ratio)))


(defmacro push (item lst)
  `(setq ,lst (cons ,item ,lst)))


(defun process ()
  (let* ((resampled (resample s resample-rate))
         (normalized (cond
                        ((= normalize-choice normalize-full)      (normalize-full resampled))
                        ((= normalize-choice normalize-balanced)  (normalize resampled))
                        ((= normalize-choice normalize-no)        (resampled))))
         (samples-array (snd-samples normalized wavesize))
         (samples-list '()))

    (dotimes (index wavesize)
      (push (n163-adjust (aref samples-array index)) samples-list))

    (reverse samples-list)
  )
)


(defun normalize (snd)
  (let ((maximum (peak snd NY:ALL)))
    (scale (/ 1.0 maximum) snd)))

(defun normalize-full (snd)
  (let* (
      (positive-snd (sum snd (peak (sum snd -100) NY:ALL) -100))
      (maximum (peak positive-snd NY:ALL))
      (zero-two (scale (/ 2.0 maximum) positive-snd))
    )
    (sum zero-two -1)))


; Converts value in range from -1.0 to 1.0 into an integer from 0 to max-volume
; Does not bother range-checking input
(defun n163-adjust (value)
  (min (float max-volume) (truncate (* (+ value 1.0) half-max-volume))))


(defun run ()
  (list (list 0 (get-duration 1) (string-trim "()" (format nil "~a" (process))))))


; Execution begins here
(if (arrayp s)
  "Stereo tracks are not supported at this time."
  (run))

## zz_beater.ny
;nyquist plug-in
;version 4
;type generate
;categories "http://lv2plug.in/ns/lv2core#GeneratorPlugin"
;name "Beat Track..."
;manpage "Beat_Track"
;preview linear
;action "Generating Beat..."
;author "Dominic Mazzoni, nyanpasu64"
;copyright "Released under terms of the GNU General Public License version 2"

;; by Dominic Mazzoni, David R. Sky and Steve Daulton.
;; Drip sound generator by Paul Beach
;; Released under terms of the GNU General Public License version 2:
;; http://www.gnu.org/licenses/old-licenses/gpl-2.0.html .


;control action "Action choice" choice "Generate track, Help screen 1, Help screen 2" 0
;control freq "Freq (ticks per second)" real "hi guys" 60 0 1000
;control timesig "Beats per measure (bar)" int "1 - 20 beats/measure" 4 1 20
;control swing "Swing amount" float "+/- 1" 0 -1 1
;control measures "Number of measures (bars)" int "1 - 1000 bars" 16 1 1000
;control click-track-dur "Optional rhythm track duration (minutes seconds)" string "Whole numbers only" ""

;;control ticklen "Individual beat duration (milliseconds)" int "1 - 100 ms" 10 1 100

;control offset "Start time offset (seconds)" real "0 - 30 seconds" 0 0 30
;control click-type "Beat sound" choice "Metronome tick,Ping,Cowbell,Resonant noise,Noise click,Drip" 4

;;control q "Noise click resonance - discernable pitch (q)" int "1 - 20" 1 1 20

;control high "MIDI pitch of strong beat" int "18 - 116" 84 18 116
;control low "MIDI pitch of weak beat" int "18 - 116" 80 18 116

;; allow q control to be commented out.
(if (not (boundp 'q))
    (setf q 10))

;; allow ticklen control to be commented out.
(if (not (boundp 'ticklen))
    (setf ticklen 10))

;; TODO: Hard code tick length (long and short versions
;; TODO: add drum sounds


(defun help1 ()
  (format nil
"Rhythm Track Generator help - screen 1 of 2

Generates a rhythm track at the selected freq, beats per
measure, and either number of measures or track duration,
using the selected sound.

'Freq': number of beats (clicks) per minute.

'Beats per measure (bar)': For example, 3/4 time means one
strong beat then two others to form one bar, repeated
depending on 'number of measures' or 'rhythm track duration'.

'Swing amount': When set to a non-zero amount, alternate
beats are delayed or advanced to give a swing feel. At
maximum / minimum settings the rhythm plays with triplet timing.

'Optional rhythm track duration': If you enter a value into this
field, either (minutes seconds - separated by a space), or
(seconds), the generated rhythm track will be at or slightly
longer than this duration: the end of the track is extended
into a whole measure if the entered duration does not
produce this. Use whole numbers only.

If you enter a value into this field, the 'number of measures'
value will be ignored.

To generate rhythm track or view help screen 2,
restart Rhythm Track and select from 'Action choice'.")) ;end of help1


(defun help2 ()
  (format nil
"Rhythm Track Generator help - screen 2 of 2

'Start time offset': makes the rhythm track start at a later
time than the very beginning (zero seconds), maximum
of 30 seconds.

'Beat sound': choose which sound to use for the beats.

'MIDI pitch of strong/weak beat': MIDI values indicate
what pitch to use. C-notes are:

24, 36, 48, 60 (middle C), 72, 84, 96, 108.
C# (C-sharp) above middle C is 61.

To generate rhythm track or view help screen 1,
restart Rhythm Track and select from 'Action choice'.")) ;end of help 2


;Check function: returns 1 on error
;min and max are allowable min and max values for arg
(defun check (arg min max)
  (if (and (>= arg min) (<= arg max)) 0 1))


;Function to convert a string into a list
(defun string-to-list (string)
  (read (make-string-input-stream (format nil "(~a)" string))))


(defun round-up (x)
  (if (> x (truncate x))
    (truncate (1+ x))
    (truncate x)))


(defun m-s-to-seconds (mslist)
  (if (= (length mslist) 1)
    ;just seconds
    (first mslist)
    ;minutes and seconds
    (+ (* 60 (first mslist))(second mslist))))


;Function to generate drip sound clicks
;code by Paul Beach www.proviewlandscape.com/liss/
;stretch-abs function makes this sound more like 'tick' sounds.
;limit hz to nyquist frequency.
(defun drip (p) ;p is pitch in hz
  (let* ((maxhz (/ *sound-srate* 2.1))
        (hz1 (min maxhz (* 2.40483  p)))
        (hz2 (min maxhz (* 5.52008  p)))
        (hz3 (min maxhz (* 8.653  p)))
        (hz4 (min maxhz (* 11.8  p))))
    (lp
      (stretch-abs 1
        (mult (exp-dec 0 0.015 0.25)
          (sim
            (mult (hzosc hz1) 0.5)
            (mult (hzosc hz2)  0.25)
            (mult (hzosc hz3)  0.125)
            (mult (hzosc hz4)  0.0625))))
    440)))


;Function used to normalize noise and tick clicks
;this function is necessary because filtering
;changes amplitude of filtered noise clicks
(defun normalize (sound)
  (scale (/ (peak sound ny:all)) sound))


;; Error Checking
(defun errorcheck ()
  ;beats per measure
  (if (= (check timesig 1 20) 1)
    (setq error-msg (strcat error-msg (format nil
"Beats per measure ~a outside valid range 1 to 20
" timesig))))

  ;number of measures
  (if (= (check measures 1 1000) 1)
    (setq error-msg (strcat error-msg (format nil
"Number of measures ~a outside valid range 1 to 1000
" measures))))

  ;time start offset
  (if (= (check offset 0 30) 1)
    (setq error-msg (strcat error-msg (format nil
"Time offset ~a outside valid range 0 to 30 seconds
" offset))))

  ; q
  (if (= (check q 1 20) 1)
    (setq error-msg (strcat error-msg (format nil
"Filter quality q ~a outside valid range 1 to 20
" q))))

  ;high MIDI pitch
  (if (= (check high 18 116) 1)
    (setq error-msg (strcat error-msg (format nil
"High MIDI pitch ~a outside valid range 18 to 116
" high))))

  ;low MIDI pitch
  (if (= (check low 18 116) 1)
    (setq error-msg (strcat error-msg (format nil
"Low MIDI pitch ~a outside valid range 18 to 116
" low))))

  ;validate string
  (if (> (length m-s) 0) ;if at least one item
    (cond
      ((or
        (> (length m-s) 2) ;there are more than 2 items or
        (not (integerp (first m-s))) ;first is not an integer or
        (and (= (length m-s) 2)(not (integerp (second m-s))))) ;second is not an integer
      (setq error-msg (strcat error-msg (format nil
"If used, 'Optional rhythm track duration' must be
entered as either one number (seconds0, or two
numbers (minutes seconds) separated by a space.
Use whole numbers only.~%"))))
      ;one or two integers
      ((and
          (= (length m-s) 1) ;one integer and
          (= (check (first m-s) 0 3660) 1)) ;outside valid range
        (setq error-msg (strcat error-msg (format nil
"~a seconds is outside valid range 0 to 3660~%" (first m-s)))))
      ;one or two integers
      ((and
        (= (length m-s) 2) ;2 integers and
        (or
          (= (check (first m-s) 0 60) 1) ;1st is outside valid range or
          (= (check (second m-s) 0 59) 1))) ;2nd is outside valid range or
        (setq error-msg (strcat error-msg (format nil
"~a is outside valid range 0 to (60 59)~%"
    m-s))))))) ;end of error checking

(defun metronome-tick (hz peak)
  (let* ((ln 300)
         (sig-array (make-array ln))
         (x 1))
    ;; generate some 'predictable' white noise
    (dotimes (i ln)
      (setf x (rem (* 479 x) 997))
      (setf (aref sig-array i) (- (/ x 500.0) 1)))
    (setf sig (sim (s-rest-abs 0.2)
                   (snd-from-array 0 44100 sig-array)))
    (setf sig
      (mult (abs-env (pwev 10 (/ ln 44100.0) 2 1 0))
            (highpass8  (lowpass2 sig (* 2 hz) 6)
                        hz)))
    (let ((gain (/ (peak sig 300))))
      ; The '1.11' factor makes up for gain reduction in 'resample'
      (mult (abs-env (pwlv 1.11 0.02 1.11 0.05 0 ))
        (jcrev (mult peak gain sig) 0.01 0.1)))))

(defun s-rest-abs (d)
  (abs-env (s-rest d)))

(defun cowbell (hz)
  (sim
    (mult (pwev 0.3 0.8 0.0005)
          (hzosc hz *tri-table*)
          (hzosc (* hz 3.46) *tri-table*))
    (mult (pwev 0.7 0.2 0.01)
          (hzosc (* hz 7.3) *tri-table*)
          (hzosc (* hz 1.52) *tri-table*))))


(defun get-metronome-tick (hz gain)
  (resample
    (sound-srate-abs 44100 (metronome-tick hz gain))
    *sound-srate*))

(defun get-ping (pitch)
  (stretch-abs ticklen
    (mult
      (control-srate-abs *sound-srate* (pwl 0.005 amp 0.995 amp 1))
      (osc pitch))))

(defun get-resonant-noise (pitch)
  (stretch-abs 0.05 ; 50 milliseconds
    (mult
      (control-srate-abs *sound-srate* (pwl 0.05 amp 0.95 amp 1))
      (normalize (lowpass2 (noise 1) (step-to-hz pitch) 20)))))

(defun get-noise-click (pitch)
  (stretch-abs 0.005
    (mult
      (control-srate-abs *sound-srate* (pwl 0.005 amp 0.995 amp 1))
      (normalize (lowpass2 (noise 1) (step-to-hz pitch) 2)))))

(defun get-drip (pitch)
  (stretch-abs ticklen
    (mult
      (control-srate-abs *sound-srate* (pwl 0.005 amp 0.995 amp 1))
      (normalize (drip (step-to-hz pitch))))))

(defun get-cowbell (pitch)
  (mult 0.8 (cowbell (step-to-hz pitch))))

;Function to make click
(defun click (type accent)
  (setq pitch (if (= accent 1) high low))
  (setq amp (if (= accent 1) 0.75 0.5))
  (case type
    (0 (get-metronome-tick (step-to-hz pitch) amp))
    (1 (get-ping pitch))
    (2 (get-cowbell pitch))
    (3 (get-resonant-noise pitch))
    (4 (get-noise-click pitch))
    (t (get-drip pitch))))


(defun swing-adjust (i val)
  (* val (/ 3.0) (rem (1+ i) 2)))

;Function to make one measure and save it in the global *measure*
(defun makemeasure ()
  (setf *measure*
    (sim
      (s-rest (* timesig beatlen)) ;required for trailing silence
      (click click-type 1) ;accented beat
      (simrep (x (- timesig 1))
        (at-abs (* beatlen (+ x 1 (swing-adjust x swing)))
            (cue (click click-type 0))))))) ;unaccented beat


(defun make-click-track (measures mdur)
  (setf *measure* (set-logical-stop (cue *measure*) (* timesig beatlen)))
  (seqrep (i measures) (cue *measure*)))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; START MAIN PROGRAM
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;view 1 of 2 help screens, or generate rhythm track
(cond ;'master' cond
  ((= action 1)(help1)); display help screen 1
  ((= action 2)(help2)) ; display help screen 2
  (t ;Run Program
    (setq len (/ (* *sound-srate* timesig measures) freq))
    (setq error-msg "") ;initialize error-msg

    ;convert minutes-seconds string to a list
    ;for example, "4 30" becomes (4 30)
    (setf m-s (string-to-list click-track-dur))

    ;run error checks on input values
    (errorcheck)

    (if (= (length error-msg) 0) ;if no errors, generate Rhythm Track
      (progn
        ; duration of 1 beat, originally statically 0.01 s
        (setf ticklen (* (max 1 (min 100 ticklen)) 0.001))
        (setf beatlen (/ freq))

        ;call function to make one measure
        (makemeasure)

        ;calculate measures from text input (if used)
        (if m-s (setq measures
          (/ (m-s-to-seconds m-s)(* timesig beatlen))))

        ;if previewing, restrict number of measures
        (let ((preview (/ (get '*project* 'preview-duration)
                          (* timesig beatlen))))
          (if (not (get '*track* 'view))  ;NIL if preview
              (setq measures (min preview measures))))

        ;round up number of measures
        (setq measures (round-up measures))

        ;add time offset and beatlen of silence to rhythm track,
        (seq
          (s-rest offset)    ;offset
          (make-click-track measures (* timesig beatlen)))) ;click track
      ;Else error message
      (setq error-msg (strcat (format nil
"Error.~%You have entered at least one invalid value:~%~%") error-msg)))))
	;nyquist plug-in
	;version 3
	;type analyze
	;name "N163/FDS waveform..."
	;action "Calculating N163/FDS waveform..."

	;control mode "Mode" choice "Namco 163,Famicom Disk System" 0
	;control wavesize-choice "Wave size (N163 only)" choice "4,8,12,16,20,24,28,32,36,40,44,48,52,56,60,64,68,72,76,80,84,88,92,96,100,104,108,112,116,120,124,128,132,136,140,144,148,152,156,160,164,168,172,176,180,184,188,192,196,200,204,208,212,216,220,224,228,232,236,240" 7
	;control normalize-choice "Normalize result" choice "no,balanced,full" 2

	; **********************************************************************
	; Namco 163/Famicom Disk System waveform tool
	; By Kef Schecter
	; Public domain
	; **********************************************************************

	(setf gc-flag nil)

	(setf mode-n163 0)
	(setf mode-fds 1)

	(setf normalize-no 0)
	(setf normalize-balanced 1)
	(setf normalize-full 2)

	(cond
	((= mode mode-n163) ; Convert from wavesize-choice table to actual
	; wave size (4, 8, 12...)
	(setf wavesize (* 4 (1+ wavesize-choice)))
	(setf max-volume 15))
	(t (setf wavesize 64) ; FDS mode
	(setf max-volume 63)))

	(setf half-max-volume (/ (+ max-volume 1) 2.0))

	(setf new-old-ratio (/ (float wavesize) len))

	(setf resample-rate (truncate (* sound-srate new-old-ratio)))


	(defmacro push (item lst)
	`(setq ,lst (cons ,item ,lst)))


	(defun process ()
	(let* ((resampled (resample s resample-rate))
	(normalized (cond
	((= normalize-choice normalize-full) (normalize-full resampled))
	((= normalize-choice normalize-balanced) (normalize resampled))
	((= normalize-choice normalize-no) (resampled))))
	(samples-array (snd-samples normalized wavesize))
	(samples-list '()))

	(dotimes (index wavesize)
	(push (n163-adjust (aref samples-array index)) samples-list))

	(reverse samples-list)
	)
	)


	(defun normalize (snd)
	(let ((maximum (peak snd NY:ALL)))
	(scale (/ 1.0 maximum) snd)))

	(defun normalize-full (snd)
	(let* (
	(positive-snd (sum snd (peak (sum snd -100) NY:ALL) -100))
	(maximum (peak positive-snd NY:ALL))
	(zero-two (scale (/ 2.0 maximum) positive-snd))
	)
	(sum zero-two -1)))


	; Converts value in range from -1.0 to 1.0 into an integer from 0 to max-volume
	; Does not bother range-checking input
	(defun n163-adjust (value)
	(min (float max-volume) (truncate (* (+ value 1.0) half-max-volume))))


	(defun run ()
	(list (list 0 (get-duration 1) (string-trim "()" (format nil "~a" (process))))))


	; Execution begins here
	(if (arrayp s)
	"Stereo tracks are not supported at this time."
	(run))
	;nyquist plug-in
	;version 4
	;type generate
	;categories "http://lv2plug.in/ns/lv2core#GeneratorPlugin"
	;name "Beat Track..."
	;manpage "Beat_Track"
	;preview linear
	;action "Generating Beat..."
	;author "Dominic Mazzoni, nyanpasu64"
	;copyright "Released under terms of the GNU General Public License version 2"

	;; by Dominic Mazzoni, David R. Sky and Steve Daulton.
	;; Drip sound generator by Paul Beach
	;; Released under terms of the GNU General Public License version 2:
	;; http://www.gnu.org/licenses/old-licenses/gpl-2.0.html .


	;control action "Action choice" choice "Generate track, Help screen 1, Help screen 2" 0
	;control freq "Freq (ticks per second)" real "hi guys" 60 0 1000
	;control timesig "Beats per measure (bar)" int "1 - 20 beats/measure" 4 1 20
	;control swing "Swing amount" float "+/- 1" 0 -1 1
	;control measures "Number of measures (bars)" int "1 - 1000 bars" 16 1 1000
	;control click-track-dur "Optional rhythm track duration (minutes seconds)" string "Whole numbers only" ""

	;;control ticklen "Individual beat duration (milliseconds)" int "1 - 100 ms" 10 1 100

	;control offset "Start time offset (seconds)" real "0 - 30 seconds" 0 0 30
	;control click-type "Beat sound" choice "Metronome tick,Ping,Cowbell,Resonant noise,Noise click,Drip" 4

	;;control q "Noise click resonance - discernable pitch (q)" int "1 - 20" 1 1 20

	;control high "MIDI pitch of strong beat" int "18 - 116" 84 18 116
	;control low "MIDI pitch of weak beat" int "18 - 116" 80 18 116

	;; allow q control to be commented out.
	(if (not (boundp 'q))
	(setf q 10))

	;; allow ticklen control to be commented out.
	(if (not (boundp 'ticklen))
	(setf ticklen 10))

	;; TODO: Hard code tick length (long and short versions
	;; TODO: add drum sounds


	(defun help1 ()
	(format nil
	"Rhythm Track Generator help - screen 1 of 2

	Generates a rhythm track at the selected freq, beats per
	measure, and either number of measures or track duration,
	using the selected sound.

	'Freq': number of beats (clicks) per minute.

	'Beats per measure (bar)': For example, 3/4 time means one
	strong beat then two others to form one bar, repeated
	depending on 'number of measures' or 'rhythm track duration'.

	'Swing amount': When set to a non-zero amount, alternate
	beats are delayed or advanced to give a swing feel. At
	maximum / minimum settings the rhythm plays with triplet timing.

	'Optional rhythm track duration': If you enter a value into this
	field, either (minutes seconds - separated by a space), or
	(seconds), the generated rhythm track will be at or slightly
	longer than this duration: the end of the track is extended
	into a whole measure if the entered duration does not
	produce this. Use whole numbers only.

	If you enter a value into this field, the 'number of measures'
	value will be ignored.

	To generate rhythm track or view help screen 2,
	restart Rhythm Track and select from 'Action choice'.")) ;end of help1


	(defun help2 ()
	(format nil
	"Rhythm Track Generator help - screen 2 of 2

	'Start time offset': makes the rhythm track start at a later
	time than the very beginning (zero seconds), maximum
	of 30 seconds.

	'Beat sound': choose which sound to use for the beats.

	'MIDI pitch of strong/weak beat': MIDI values indicate
	what pitch to use. C-notes are:

	24, 36, 48, 60 (middle C), 72, 84, 96, 108.
	C# (C-sharp) above middle C is 61.

	To generate rhythm track or view help screen 1,
	restart Rhythm Track and select from 'Action choice'.")) ;end of help 2


	;Check function: returns 1 on error
	;min and max are allowable min and max values for arg
	(defun check (arg min max)
	(if (and (>= arg min) (<= arg max)) 0 1))


	;Function to convert a string into a list
	(defun string-to-list (string)
	(read (make-string-input-stream (format nil "(~a)" string))))


	(defun round-up (x)
	(if (> x (truncate x))
	(truncate (1+ x))
	(truncate x)))


	(defun m-s-to-seconds (mslist)
	(if (= (length mslist) 1)
	;just seconds
	(first mslist)
	;minutes and seconds
	(+ (* 60 (first mslist))(second mslist))))


	;Function to generate drip sound clicks
	;code by Paul Beach www.proviewlandscape.com/liss/
	;stretch-abs function makes this sound more like 'tick' sounds.
	;limit hz to nyquist frequency.
	(defun drip (p) ;p is pitch in hz
	(let* ((maxhz (/ sound-srate 2.1))
	(hz1 (min maxhz (* 2.40483 p)))
	(hz2 (min maxhz (* 5.52008 p)))
	(hz3 (min maxhz (* 8.653 p)))
	(hz4 (min maxhz (* 11.8 p))))
	(lp
	(stretch-abs 1
	(mult (exp-dec 0 0.015 0.25)
	(sim
	(mult (hzosc hz1) 0.5)
	(mult (hzosc hz2) 0.25)
	(mult (hzosc hz3) 0.125)
	(mult (hzosc hz4) 0.0625))))
	440)))


	;Function used to normalize noise and tick clicks
	;this function is necessary because filtering
	;changes amplitude of filtered noise clicks
	(defun normalize (sound)
	(scale (/ (peak sound ny:all)) sound))


	;; Error Checking
	(defun errorcheck ()
	;beats per measure
	(if (= (check timesig 1 20) 1)
	(setq error-msg (strcat error-msg (format nil
	"Beats per measure ~a outside valid range 1 to 20
	" timesig))))

	;number of measures
	(if (= (check measures 1 1000) 1)
	(setq error-msg (strcat error-msg (format nil
	"Number of measures ~a outside valid range 1 to 1000
	" measures))))

	;time start offset
	(if (= (check offset 0 30) 1)
	(setq error-msg (strcat error-msg (format nil
	"Time offset ~a outside valid range 0 to 30 seconds
	" offset))))

	; q
	(if (= (check q 1 20) 1)
	(setq error-msg (strcat error-msg (format nil
	"Filter quality q ~a outside valid range 1 to 20
	" q))))

	;high MIDI pitch
	(if (= (check high 18 116) 1)
	(setq error-msg (strcat error-msg (format nil
	"High MIDI pitch ~a outside valid range 18 to 116
	" high))))

	;low MIDI pitch
	(if (= (check low 18 116) 1)
	(setq error-msg (strcat error-msg (format nil
	"Low MIDI pitch ~a outside valid range 18 to 116
	" low))))

	;validate string
	(if (> (length m-s) 0) ;if at least one item
	(cond
	((or
	(> (length m-s) 2) ;there are more than 2 items or
	(not (integerp (first m-s))) ;first is not an integer or
	(and (= (length m-s) 2)(not (integerp (second m-s))))) ;second is not an integer
	(setq error-msg (strcat error-msg (format nil
	"If used, 'Optional rhythm track duration' must be
	entered as either one number (seconds0, or two
	numbers (minutes seconds) separated by a space.
	Use whole numbers only.~%"))))
	;one or two integers
	((and
	(= (length m-s) 1) ;one integer and
	(= (check (first m-s) 0 3660) 1)) ;outside valid range
	(setq error-msg (strcat error-msg (format nil
	"~a seconds is outside valid range 0 to 3660~%" (first m-s)))))
	;one or two integers
	((and
	(= (length m-s) 2) ;2 integers and
	(or
	(= (check (first m-s) 0 60) 1) ;1st is outside valid range or
	(= (check (second m-s) 0 59) 1))) ;2nd is outside valid range or
	(setq error-msg (strcat error-msg (format nil
	"~a is outside valid range 0 to (60 59)~%"
	m-s))))))) ;end of error checking

	(defun metronome-tick (hz peak)
	(let* ((ln 300)
	(sig-array (make-array ln))
	(x 1))
	;; generate some 'predictable' white noise
	(dotimes (i ln)
	(setf x (rem (* 479 x) 997))
	(setf (aref sig-array i) (- (/ x 500.0) 1)))
	(setf sig (sim (s-rest-abs 0.2)
	(snd-from-array 0 44100 sig-array)))
	(setf sig
	(mult (abs-env (pwev 10 (/ ln 44100.0) 2 1 0))
	(highpass8 (lowpass2 sig (* 2 hz) 6)
	hz)))
	(let ((gain (/ (peak sig 300))))
	; The '1.11' factor makes up for gain reduction in 'resample'
	(mult (abs-env (pwlv 1.11 0.02 1.11 0.05 0 ))
	(jcrev (mult peak gain sig) 0.01 0.1)))))

	(defun s-rest-abs (d)
	(abs-env (s-rest d)))

	(defun cowbell (hz)
	(sim
	(mult (pwev 0.3 0.8 0.0005)
	(hzosc hz tri-table)
	(hzosc (* hz 3.46) tri-table))
	(mult (pwev 0.7 0.2 0.01)
	(hzosc (* hz 7.3) tri-table)
	(hzosc (* hz 1.52) tri-table))))


	(defun get-metronome-tick (hz gain)
	(resample
	(sound-srate-abs 44100 (metronome-tick hz gain))
	sound-srate))

	(defun get-ping (pitch)
	(stretch-abs ticklen
	(mult
	(control-srate-abs sound-srate (pwl 0.005 amp 0.995 amp 1))
	(osc pitch))))

	(defun get-resonant-noise (pitch)
	(stretch-abs 0.05 ; 50 milliseconds
	(mult
	(control-srate-abs sound-srate (pwl 0.05 amp 0.95 amp 1))
	(normalize (lowpass2 (noise 1) (step-to-hz pitch) 20)))))

	(defun get-noise-click (pitch)
	(stretch-abs 0.005
	(mult
	(control-srate-abs sound-srate (pwl 0.005 amp 0.995 amp 1))
	(normalize (lowpass2 (noise 1) (step-to-hz pitch) 2)))))

	(defun get-drip (pitch)
	(stretch-abs ticklen
	(mult
	(control-srate-abs sound-srate (pwl 0.005 amp 0.995 amp 1))
	(normalize (drip (step-to-hz pitch))))))

	(defun get-cowbell (pitch)
	(mult 0.8 (cowbell (step-to-hz pitch))))

	;Function to make click
	(defun click (type accent)
	(setq pitch (if (= accent 1) high low))
	(setq amp (if (= accent 1) 0.75 0.5))
	(case type
	(0 (get-metronome-tick (step-to-hz pitch) amp))
	(1 (get-ping pitch))
	(2 (get-cowbell pitch))
	(3 (get-resonant-noise pitch))
	(4 (get-noise-click pitch))
	(t (get-drip pitch))))


	(defun swing-adjust (i val)
	(* val (/ 3.0) (rem (1+ i) 2)))

	;Function to make one measure and save it in the global measure
	(defun makemeasure ()
	(setf measure
	(sim
	(s-rest (* timesig beatlen)) ;required for trailing silence
	(click click-type 1) ;accented beat
	(simrep (x (- timesig 1))
	(at-abs (* beatlen (+ x 1 (swing-adjust x swing)))
	(cue (click click-type 0))))))) ;unaccented beat


	(defun make-click-track (measures mdur)
	(setf measure (set-logical-stop (cue measure) (* timesig beatlen)))
	(seqrep (i measures) (cue measure)))


	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
	;; START MAIN PROGRAM
	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

	;view 1 of 2 help screens, or generate rhythm track
	(cond ;'master' cond
	((= action 1)(help1)); display help screen 1
	((= action 2)(help2)) ; display help screen 2
	(t ;Run Program
	(setq len (/ (* sound-srate timesig measures) freq))
	(setq error-msg "") ;initialize error-msg

	;convert minutes-seconds string to a list
	;for example, "4 30" becomes (4 30)
	(setf m-s (string-to-list click-track-dur))

	;run error checks on input values
	(errorcheck)

	(if (= (length error-msg) 0) ;if no errors, generate Rhythm Track
	(progn
	; duration of 1 beat, originally statically 0.01 s
	(setf ticklen (* (max 1 (min 100 ticklen)) 0.001))
	(setf beatlen (/ freq))

	;call function to make one measure
	(makemeasure)

	;calculate measures from text input (if used)
	(if m-s (setq measures
	(/ (m-s-to-seconds m-s)(* timesig beatlen))))

	;if previewing, restrict number of measures
	(let ((preview (/ (get 'project 'preview-duration)
	(* timesig beatlen))))
	(if (not (get 'track 'view)) ;NIL if preview
	(setq measures (min preview measures))))

	;round up number of measures
	(setq measures (round-up measures))

	;add time offset and beatlen of silence to rhythm track,
	(seq
	(s-rest offset) ;offset
	(make-click-track measures (* timesig beatlen)))) ;click track
	;Else error message
	(setq error-msg (strcat (format nil
	"Error.~%You have entered at least one invalid value:~%~%") error-msg)))))