“What makes the thing play?” That’s the simple question asked by Charles Amirkhanian early in the first of two hours of interviews he and Bill Schechner did with player-piano enthusiasts back in the early 1970s. They’re now available as a pair of MP3s from archive.org (MP3, MP3). A few sentences into the answer from a member of the Automatic Musical Instrument Collectors Association (AMICA), Amikhanian asks to back up a bit, from the mechanisms of playback to the recording process itself. He compares the piano rolls to a mix between Torah scrolls and computer punch cards, and the conversation quickly gets into the realm of “impossible” music produced on the player piano, of composers interested in “doing piano work separate from the pianist,” things that even things two pianists working in tandem couldn’t coordinate. It’s a great glimpse not only into an early form of high-tech home entertainment, but into the passions of the vacuum-powered form’s preservationists. And the recordings include the audio of numerous old rolls.