Metheny doubles the pleasure

What's the difference between a band and a group? The distinction may seem insignificant, but it's definitely meaningful to Pat Metheny.

Between his latest ensemble's self-titled 2012 debut and its new follow-up, Kin, the Pat Metheny Unity Band became the Unity Group. The change entailed the addition of Italian multi-instrumentalist Giulio Carmassi and a more orchestral approach to repertoire.

The Keswick's marquee Saturday promised the Unity Group, but enthusiastic listeners essentially got two bands/groups for one ticket. The first half of the set featured the core quartet focused on music from the 2012 album, so that, as Metheny said, "we get to be our own opening act."

It was a rare case of openers threatening to overshadow the headliners. Honed by months of touring behind the Unity Band album, these songs elicited some of the night's most fiery and intricate soloing. Metheny unleashed molten lines from his guitar-synth on "Roofdogs." Saxophonist Chris Potter plunged into his tenor's honking low register, responding to drummer Antonio Sanchez's tumultuous instigations on "Come and See." The half ended with "James," from 1982's Offramp, the cheery melody giving way to a duet between guitarist and drummer that showed why Sanchez has been the constant in all Metheny's recent ensembles.

Carmassi entered as Metheny unveiled the "orchestrion," a battery of mechanical instruments including a range of percussion and shelves of bottles that made the stage resemble an Old West saloon. On Kin's title track, Carmassi's keyboards and the hobby-kit symphony added lush atmospherics but the (often literal) bells and whistles detracted from the powerhouse quartet.

Momentum picked up with some improv leading into the Ornette Coleman-esque "Genealogy." The night neared its close with duets, including a lovely "Bright Size Life" with bassist Ben Williams, a bop-flavored face-off with Potter, and a Carmassi vocal/ piano showcase.