COMMENT ⊗   VALID 00003 PAGES
C REC  PAGE   DESCRIPTION
C00001 00001
C00002 00002	.DEVICE XGP
C00003 00003	!group skip 2
C00011 ENDMK
C⊗;
.DEVICE XGP
.SPACING 10*5 MILLS;
.FONT 1 "BASL30"
.FONT 2 "BASI30"
.FONT 3 "BASB30"
.FONT 4 "BDR40"
.FONT 5 "FIX25"
.FONT 6 "BDI25"

.TURN ON "≡" FOR "%";
.PAGE FRAME 44 HIGH 78 WIDE
.TITLE AREA HEADING LINES 1 TO 2
.AREA TEXT LINES 3 TO 44
.PLACE HEADING
.SELECT 1
.PLACE TEXT
.NOJUST
.NOFILL
.SELECT 1
.NEXT PAGE
.TABS 9,17,25,33,41,49,57,65,73,81,89;
.TURN ON "\";
.COMMAND CHARACTER "!";

!group skip 2
!begin center
≡4SOUND SYNTHESIS AND CONTROL OF TIMBRE≡1


PROBLEM 2
!end

!begin fill adjust
≡3Here we have the instrument block diagram, instrument code, and
the function of the parameters for an instrument which is designed to
produce vibrato.  The instrument also has an oscilator to control the
amplitude of the output wave (amplitude envelope).
The frequency, P3, is the average frequency while the frequency deviation,
P5, determines the number of cycles above and below its average the frequency
will deviate.  The frequency, P6, is the rate at which the deviation will
occur (moduation frequency).≡5
!END
!GROUP SKIP 18
!SELECT 5
P1       P2     P3     P4     P5     P6     P7      P8     P9
Beg      Dur    Freq   Amp    Freq   Mod    Amp     Mod    Output
                              dev.   freq   env     wave   wave

0        1      440    1000   5      6      F2      F1     F3
!BEGIN FILL ADJUST

≡31.  How can we add an OSCIL to this instrument such that the frequency
deviation will increase and decrease as the amplitude (envelope) of the
output wave increases and decreases.  The maximum deviation will again be
determined by P5.
!END