hsc3-0.18: Help/UGen/done.help.lhs
> import Sound.SC3 {- hsc3 -}
> g_01 =
> let x = mouseX KR (-1) 1 Linear 0.1
> e = linen x 0.1 0.1 0.5 DoNothing
> o1 = sinOsc AR 880 0 * 0.1
> o2 = sinOsc AR 440 0 * e
> in mce [done e * o1,o2]