Next we'll animate the basic sound by mixing it with two slightly de-tuned copies of itself. We'll employ Csound's cpspch value converter which will allow us to specify the pitches by octave and pitch-class rather than by frequency, and we'll use the ampdb converter to specify loudness in dB rather than linearly.

Since we are adding the outputs of three oscillators, each with the same amplitude envelope, we'll scale the amplitude before we mix them. Both iscale and inote are arbitrary names to make the design a bit easier to read. Each is an i-rate variable, evaluated when the instrument is initialized.

instr 4	; toot4.orc
	iamp	=	ampdb(p4)	; convert decibels to linear amp
	iscale	=	iamp * .333	; scale the amp at initialization
	inote	=	cpspch(p5)	; convert "octave.pitch" to cps
	k1	linen	iscale, p6, p3, p7	; p4=amp
	a3	oscil	k1, inote*.996, 1	; p5=freq
	a2	oscil	k1, inote*1.004, 1	; p6=attack time
	a1	oscil	k1, inote, 1	; p7=release time
	a1	=	a1 + a2 + a3
	out	a1
endin