01_41_1
additional parameters: ifqr, iamp1, irate


In this instrument we find a RANDI unit generator at the place
usually occupied by the envelope. The center frequency of the
noise band generated by RANDI varies with the pitch of the wave
oscillator. 

The pitch control function works exactly as in instrument
01_40_1; except that irate is now duration independent. Function
table f33 is scanned at a rate of 3 Hz for 6.5 seconds, repeating
a frequency descent of two octaves. We want to leave it for
further experimentation to the reader to find out more about the
glissando of a pitched noise band. The sounds unpleasantly remind
us of certain noise pollutions.

The bad cutoffs can be eliminated by supplying an envelope.
(Risset 1969: #511) 

(flowchart)
(.orc and .sco files)

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01_42_1
additional parameters: ifc, iwidth, irate, ifm


This instrument permits us to add a frequency vibrato to a sound.
All notes have a duration of one second. In this special case the
vibrato rate is neither duration dependent, nor duration
independent. 

The vibrato width is limited to subaudio frequencies. This run
shows a quick experimentation with two sets of three notes each.
The variable iwidth takes the values 8, 16 and 24 in turn. In the
first set the rate of the vibrato is 5 Hz, in the second set it
is 2 Hz.

The use of an adder in the instrument allows to switch off the
vibrato by setting iwidth to 0.

(flowchart)
(.orc and .sco files)

