apeSoft, developer of iVCS3 and iDensity, has released a unique performance app based on algorithms. I can't even pretend to understand half of what's going on here, but fortunately there's a demo video! Oh yeah, and it's free!
SOLO [Nr.19] iTunes Description:
SOLO [Nr.19] is an algorithm that aims to implement digitally the original analog set-up for the performance of six versions of Solo für melodieninstrument mit rückkopplung by Karlheinz Stockhausen.
The original composition was conceived for five persons. Four technicians plus the main instrument performer. SOLO [Nr.19], performs the work of four technicians for each of the six Stockhausen's versions.
In Demo mode you can hear the first version of “Solo” composition performed by Enrico Francioni, Contrabass. With In-App features, you will be able to feed algorithm with your audio Live.