The "Orchestrion" was a 19th century hybrid musical instrument that usually contained a wind orchestra, various percussion instruments, and sometimes a piano played by a pinned cylinder or a music roll.

Pat Metheny designed and played his own version of one -- thanks to a commissioned group of inventors, advanced solenoid switch technology, and pneumatics -- on the 2010 album Orchestrion.

The guitarist's version combined organic instruments -- various pianos, basses, rows of tuned bottles, bells, cymbals, and other percussion, with digital technology -- guitarbots (including one modeled on Paolo Angeli's guitar), switches, and more.

The Orchestrion Project was recorded following Metheny's world tour with the instrument, wherein he discovered more about the instrument and its capabilities for group interplay in a solo setting.

This was recorded in the same vacant church space as the original; it features the tour itinerary, tune for tune.

Metheny played each selection several times and kept the best takes.

This double disc contains four substantially revised versions of Orchestrion numbers and two new improvisations -- in particular the extended "Improvisation #2," with its layers of electric guitars, basslines, bells, and percussion including staggered marimbas that weave counter-melodic lines around the guitar vamps.

The blown bottle sounds actually sound like flutes.

In addition are several catalog items rearranged for the instrument: there are gorgeous readings of "Antonia" and "Tell Her You Saw Me" from Secret Story, a short version of Ornette Coleman's "Broadway Blues," a "drum'n'bass" take on We Live Here's "Stranger in Town," and a sparse "Unity Village" from Bright Size Life.

This last cut is introduced by a long, knotty, boppish guitar solo that eventually unfolds into the more elegant and flowing narrative we know -- though without the rhythmic invention that Bob Moses and Jaco Pastorius brought to the original.

In fact, Metheny deliberately keeps the tempo fixed in the accompanied section, as if to acknowledge that these players cannot be replaced; the tune becomes something other, something wholly different in this context.

Other than this instance and some sparse minimal accompaniment in the bluesy "Improvisation #1," the Orchestrion as an instrument offers fluid, organic-sounding, full accompaniment and interaction.

It doesn't replace a band, but it isn't meant to; instead it serves as the extension of Metheny's voice as composer, arranger, and improviser, allowing him to express on multiple levels simultaneously while playing solo.

While this album's predecessor evidenced his accomplishment in the instrument's creation and operation, The Orchestrion Project reveals that Metheny's possibilities with it have only been tapped.