hsc3-0.18: Help/UGen/bHiPass4.help.lhs
> import Sound.SC3 {- hsc3 -}
> g_01 =
> let i = mix (saw AR (mce [0.99, 1, 1.01] * 440) * 0.3)
> f = mouseX KR 20 20000 Exponential 0.2
> rq = mouseY KR 0.1 1 Linear 0.2
> in bHiPass4 i f rq