Taming the Elements with MIDI: "Trimpin's interest in the work of Nancarrow led him to build a device that optically reads Nancarrow's rolls and records the data on a computer for transcription into MIDI song files.

Then he built a device that mechanically depresses the piano keys, in order to play Nancarrow's pieces and other demanding compositions. (According to Trimpin, this device is still the only way to play Nancarrow's pieces on a real piano under MIDI control.

Commercially available MIDI pianos, such as the Yamaha Disklavier, cannot play pieces as dense and complex as Nancarrow's.)"