Imagine a player piano that can play along with a live human, weaving intricate harmonies and rhythms based on what the pianist is playing but modified by algorithms that invert, echo, or otherwise mimic the live performance to provide, in essence, a robot accompanist. It may sound like something out of Westworld, but it’s actually the method jazz pianist Dan Tepfer uses in his improvisational live performances and on his new album, Natural Machines, which has its digital release on May 17, 2019. We spoke with Tepfer about how he came up with the idea of playing alongside a computer and using math with music.