Since the mid-1970s, guitarist Pat Metheny has played in all kinds of groups: duos, trios, quartets, big bands, you name it. But 2010’s Orchestrion is unlike anything he’s ever done. After a casual listen, you probably wouldn’t know that this is a solo record; it sounds like the work of a medium-size ensemble. In fact, the guitarist is playing with a Metheny-programmed automaton orchestra that includes pianos, marimba, vibraphone, guitarbots, keyboard, percussion, and a variety of “custom-fabricated acoustic mechanical instruments.” The sounds can be triggered via guitar, keyboard, or computer. Amazingly, the music flows in human-like ways. There are occasional hints of the mechanistic —“Entry Point,” for instance, has stiff touches you might expect to hear from such a contraption. At various points, the plinking percussion brings to mind minimalist composers such as Steve Reich or Philip Glass. The self-titled opening track is representative of the whole: a lush arrangement provides a backdrop for Metheny’s fluid guitar. Orchestrion is an appealing, subtly strange album that isn’t quite like anything else.