Step 2:

In Step 2 the orchestra becomes both more complex and more versatile. Four global effects units were added; reverb, delay, comb filter and chorus. As noted in the list of constraints, above, it was desirable to make the choice as to which would be utilized variable on an event by event basis for each instrument. The imodsel variable in instrument 1 allows for a number between 1 and 4 in pfield 8 of the score to determine which global variable would be activated at initialization time for each event. The kpan variable determines the panning for each event at the control rate. Values between 0 and 1, to one decimal place, determine a static panning position while a value above 1 up to 9 would determine a dynamic panning position depending on the envelope controlling it. (Panning modulation is a very powerful tool for creating space in a composition. With it an envelope determines the position of the source sound, which moves through the stereo panorama in time.) Also the sample number is a variable in the score at pfield 7, isfile. This allows for a set of “possible” samples being available according to a weighted distribution. The possible samples are determined in the sub-score as stipulated by the schema. Figure 9 is one of four identical instruments utilized for this step.

* Fig. 11 (below) The sample numbers in the gray cells are links to an mp3 of the sample.

;Global Variables (Modifiers)

garvb init 0
gadelay init 0
gacomb init 0
gachorus init 0

instr 1
idur = p3
iamp = p4
ifreq = p5
kpan = p6
isfile = p7
imodsel =p8

iatk = p3 * .1
idec = p3 * .2

;pan envelopes
kenv1 linseg 0, idur * .5, 1, idur * .5, 0
kenv2 linseg 1, idur * .5, 0, idur * .5, 1
kenv3 linseg 0, idur, 1
kenv4 linseg 1, idur, 0
kenv5 linseg 0, idur * .5, .5, idur * .5, 0
kenv6 linseg 1, idur * .5, .5, idur * .5, 1
kenv7 linseg 0, idur * .5, .75, idur * .5, 0
kenv8 linseg 1, idur * .5, .25, idur * .5, 1

;amplitude envelopes
kenv11 linseg 0, iatk, iamp, idur – (iatk + idec), iamp, idec, 0

a1, a2 diskin isfile, ifreq, 0, 1
a3 = a1 * kenv11
a4 = a2 * kenv11

kenv20 = (kpan <3 ? kenv1:kenv2)
kenv21 = (kpan =4 ? kenv3:kenv20)
kenv22 = (kpan =5 ? kenv4:kenv21)
kenv23 = (kpan =6 ? kenv5:kenv22)
kenv24 = (kpan =7 ? kenv6:kenv23)
kenv25 = (kpan =8 ? kenv7:kenv24)
kenv26 = (kpan =9 ? kenv8:kenv25)
kbal = (kpan <=1 ? kpan:kenv26)

;modulator select
if imodsel = 4 goto out4
if imodsel = 3 goto out3
if imodsel = 2 goto out2

outs a3 * (kbal – 1), a4 * kbal
garvb = garvb + ((a3 + a4) * .25)

if imodsel = 1 goto end

out2:
outs a3 * (kbal – 1), a4 * kbal
gadelay = gadelay + ((a3 + a4) * .5)

if imodsel = 2 goto end

out3:
outs a3 * (kbal – 1), a4 * kbal
gacomb = gacomb + ((a3 + a4) * .5)

if imodsel = 3 goto end

out4:

outs a3 * (kbal – 1), a4 * kbal
gachorus = gachorus + ((a3 + a4) * .5)

end:

endin

Figure 9: Excerpt from Step2 orchestra

Below is an excerpt of a sub-score (Cmask file) that was used in conjunction with the Step 2 instruments to render the sample results for Step 2:

;init global instruments

{
i5 0 110 ;global variable and associated start times
i6 0 110
i7 0 110
i8 0 110
}

;instr1 ;instrument number

f 7 75

;Field start time and duration

p1 const 1;instrument number constant

p2

;start time
rnd uni ;random uniform distribution
mask (0 10 60 10) (0 27.5 60 25);Time Value Time Value …
prec 2 ;two decimal places

p3

;idur
rnd uni ;random uniform distribution
mask (0 10 20 15 45 12) (0 17 40 15 45 18) ;Time Value Time Value …
prec 2 ;two decimal places

p4

;amp
rnd uni ;random uniform distribution
mask (0 .35 75 .40) (0 .45 75 .60) ;mask .35 .75
prec 2 ;two decimal places

p5

;ifreq
rnd uni ;random uniform distribution
range -.25 4.25 ;range of values
prec 2 ;two decimal places

p6 ;kpan (0 – 8)
item swing (0 .1 .2 .3 .4 .5 .5 .6 .7 .8 .9 1 2 3 4 5 6 7 8 9) ;swing distribution of values listed
prec 1 ;one decimal point

p7;isfile select sample file
item random (1311 1312 1311 1314);random distribution of values listed

p8 ;imodsel
item heap (1 2 3 4) ;heap distribution of values listed
prec 0 ;no decimal place

Figure 10: Excerpt from one of many sub-scores (Cmask files).

Figure 11: A section of the Schema for Step 2

*The sample numbers in the gray cells are links to an mp3 of the sample.

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