Cool demonstration of Silk Road a "tangible interface":
"Silk Road is a tangible interface combined with original musical content, suited to concert performance or interactive installation. The interface uses minimal hardware – a single contact microphone – to turn an everyday surface such as a table top into a responsive and user-discoverable performance device. Two principal gestures, RUB and TAP, are derived by feature recognition on the FFT decomposition of the microphone signal. More complex control gestures arise from combinations of the basic pair (Quick rub followed closely by one tap: maximize sustain of sound. Quick tap followed closely by rub: start loop recording (rub to stop & play). Etc).
Silk Road began its life as an acousmatic composition, based on instrumental material with overt melody, rhythm, and harmony. The acousmatic work is imbedded in the software realisation (Max, Ableton Live, and Reaktor), and in the choices of gesture mapping, such that the user/player is able to deconstruct and reinvent the musical material. User gestures act as control for the triggering and parametric control of playback and sound transformation on a library of sound clusters derived from the original composition; but this control passes through a stochastic layer so that the system also creates its own variety and a resulting stimulus to the user. Silk Road has been tested with a number of users and has been found to be rewarding both to extended free-form play and to the creation of performances shaped through time. The system has also be tested successfully with different musical source material."