Source: Piano Genie: An Intelligent Musical Interface
Piano Genie is in some ways reminiscent of video games such as Rock Band and Guitar Hero that are accessible to novice musicians, with the crucial difference that users can freely improvise on Piano Genie rather than re-enacting songs from a fixed repertoire.
They trained a machine learning model on ~1400 virtuosic performances from the International Piano-e-Competition in order to map 8-button input to a full 88-key piano in real time.
Interactive Web Demo: https://tensorflow.github.io/magenta-demos/piano-genie/