Adam Parrish:

The Frotzophone is an interface for making music with interactive fiction. The topography simulated in the game is used to generate sound, as is the player’s path through the game. A Frotzophone “performance” looks just like playing a text adventure; but in addition to playing a game, you’re also playing music.
Here’s a sample of the Frotzophone’s audio output. This sample was generated from playing the first part of Zork I–up until I got killed by the troll. Download the full track here (2’12”, 192kbps MP3).