You’re the only human onstage at Town Hall on Friday. You’ve got your foot pedals and five or six guitars, but also there’s an orchestrion behind you, under wraps — instruments in cages and carpentry, on rods and risers — and 1,500 people before you.

Image Pat Metheny at Town Hall on Friday night accompanying and being accompanied by his orchestrion, an electronic and mechanical orchestra worthy of Rube Goldberg. Credit... Rahav Segev for The New York Times

They’ve never seen anything quite like this before. It’s best not to overwhelm them, so you begin with solo guitar: several pieces you’ve recorded over the last three years with Brad Mehldau, and a song (“Unity Village”) from your first album. It’s pretty strummy, a lot of parallel chords. Then you un-tarp the imaginarium, the crowd says, “Whoa!,” and you start activating things.

You haven’t compromised in the music for “Orchestrion,” the new Nonesuch recording of this colossus: a suite, through-composed, rhythmically complex, Brazilian-ish in parts, powered by the counterpoint of mallet instruments, with sections of static harmony as an open background for your guitar solos. It’s very dense, though. You’ve made that machine prove itself. The biggest challenge — as it was for the player-piano industry — is rhythm and dynamics. How do you make rhythm sound comfortable, and not as if it’s made by a robot?

You introduce maximum bend and bounce into the mallets so there’s a little pliancy to the beat and attach different kinds of strikers to every cymbal: a stick and a mallet for each, programmed to hit the cymbal at staggered intervals, presumably so that you don’t feel drilled by only one sound, one color. Except for some of the drumming it sounds pretty much like people playing these instruments; it seems to push robotic humanism to the limit. There are no wind instruments here, or fake voices (not counting the bottle-whooshing). That would be too much.

All these tiny decisions! The hardware, the mechanics. The expense. You provide an overall explanation, because people will riot if you don’t, but can you even try to break it down? “To really explain takes three hours,” you say, pre-emptively.