# Fwd: [CM] a FOMUS problem

Rick Taube taube@uiuc.edu
Sat, 1 Apr 2006 22:50:57 -0600

```Here are 2 polyphonic Fomus examples. unfortunatly the ring modulation
one triggers a fomus array index error that didnt happen last fall. the
midi file from it seems to be ok.

--------
(in-package cm)
(use-system :fomus)

;;;
;;; 5-voice Harmonics "Etude"
;;;

(defun play-harmonics (note beat harm1 harm2)
(process for h from harm1 to harm2
for f = (* (hertz note) h)
output (new note :off (now) :dur (rhythm beat)
:note (keynum f :hz) :partid harm1)
wait (rhythm beat)))

(defparameter primes '(2 3 5 7 11))

(defparameter cellos (loop for p in primes
collect (new part :partid p :instr :cello)))

(events (process for p in primes
sprout (play-harmonics 'c1 (/ 1 p) p (* p 4)))
"primes.ly" :quartertones t :max-tuplet 11
:parts (reverse cellos) :view t)

(events (process for p in primes
sprout (play-harmonics 'c1 (/ 1 p) p (* p 4)))
"primes.mid" :channel-tuning 8 :tempo 40)

;;;
;;; Ring Modulation Etude
;;;

(defun random-rm (num notes)
(process with pat = (new heap :of notes
:for (new weighting :of '(1 2 3)))
repeat num
for set1 = (next pat t)
for set2 = (next pat t)
for set3 = (rm-spectrum set1 set2 :spectrum ':note
:remove-duplicates t)
for reps = (pick 3 4 5)
sprout (process with pat = (new cycle :of (list set1 set2)
:repeat reps)
for c = (next pat)
until (eod? c)
each k in c output (new midi :time (now)
:keynum k
:channel 0
:duration .25
:amplitude .2)
wait .25)
sprout (process with pat = (new cycle :of set3)
repeat (* 2 reps)
output (new midi :time (now)
:keynum (next pat)
:channel 1
:duration .125
:amplitude .4)
wait .25)
wait (* .25 reps 2)))

(defparameter duo (list (new part :partid 0 :instr ':viola)
(new part :partid 1 :instr ':piano)))

(defparameter mus (new seq))

(events (random-rm 16 (loop for i from 60 to 72 collect i)) mus)

(events mus "rm-etude.mid" :tempo 80)

(events mus "rm-etude.ly" :parts duo :view t)

Array index -1 out of bounds for #(",,," ",," "," "" "'" "''" "'''"
"''''"
"'''''") .
[Condition of type SIMPLE-ERROR]

Restarts:
0: [ABORT-REQUEST] Abort handling SLIME request.
1: [ABORT-BREAK] Reset this process
2: [ABORT] Kill this process

Backtrace:
0: (FOMUS::LYNOTE 11 0 0 'NIL 'NIL)
1: (FOMUS::SAVE-LILYPOND '(#1=#Z(FOMUS:PARTEX :ID NIL :PARTID 1 :NAME
NIL :ABBREV NIL :INSTR ...) #1#(FOMUS:PARTEX :ID NIL :PARTID 0 :NAME
NIL :ABBREV NIL :INSTR ...)) "% LilyPond score file
% FOMUS v0.1.54

```