xOut bufferIndex xFade inputs
 
Send signal to a bus, crossfading with existing contents.

> let p a b = sinOsc AR (MCE [a, b]) 0 * 0.1
>     x     = mouseX KR 0 1 Linear 0.1
>     y     = mouseY KR 0 1 Linear 0.1
> audition (MRG [ out  0   (p 220 221)
>               , xOut 0 x (p 330 331)
>               , xOut 0 y (p 440 441)
>               , out  0   (p 120 121)])