I remember a lecturer on our Music Tech Master's playing this video, of a caged flame being bombarded with extremely high amplitude sound waves (I think), turning the flame into a loudspeaker.......just as freaky
I saw an installation of that talking piano some years ago. It is by Peter Ablinger, a german composer. I remember seeing a laptop beneath the piano, running PureData. Maybe pd just played midi data - but who knows...
Peter Ablinger gave a 3-minute talk on the "piece". He only mentioned that it involved a sophisticated algorithm for finding the best resynthesis, on which he worked for a long time.
I think there might be some publications on this technique, as this approach is quite popular with some instrumental composers of so called "spectral music".