Someone’s booking agent deserves a raise. The idea of the xx and Grizzly Bear touring together doesn’t make much sense, until you see the pairing live. Their styles fall on polar ends of the spectrum, but in a back-to-back setting, they make for a compelling match. One blows the balloon up, the other deflates it.
From London, the xx is essentially a trio of architects masquerading as musicians. Their songs are models of grace and economy, shot through with shimmering, repeating guitar lines and a tremendous amount of space. Nothing is out of place with this band, from the elliptical singing style of guitarist Romy Madley Croft and bassist Oliver Sim to Jamie xx’s throbbing sonic backdrops.
Grizzly Bear, meanwhile, takes a widescreen approach to its music, filling nearly every pocket with grandeur and sweeping melodies. Singers Ed Droste and Daniel Rossen luxuriate in the grand vocal tradition of wounded crooners like Morrissey. Grizzly Bear tends to unfurl across the horizon.
Saturday night at the Bank of America Pavilion, with a breeze wafting in from the harbor, the xx and Grizzly Bear were an inspired twofer. In its headlining set, the xx proved they have grown as performers since emerging in 2009. Together the three musicians share a delicate balance. Each part is elemental; take out Madley Croft’s guitar work, and suddenly the bass lines fall flat. Likewise, without Jamie xx’s arrangements, which have grown more dance-oriented, the songs would come off too monochromatic.
As on their records, Madley Croft and Sim shared vocal duties, and their chemistry has become even more coy. At several points they sauntered over to the other, their bodies and instruments undulating like gentle waves at high tide. Blinding white lights, stage smoke, and lasers added considerably to the ethereal effects of the music.
For such stoic song structures, the xx’s lyrics are often unequivocally emotional — gut-wrenching, even. “When I see you again/ And I’m greeted as a friend/ It is understood/ That we did all we could,” Sim sang on “Sunset,” from the band’s most recent album, “Coexist.”
In a testament to how consistent the band has been, older songs (“VCR,” “Intro,” “Shelter”) sounded like refined but natural extensions of the new album, which added subtle textures to the xx’s palette, including Jamie xx’s wash of steel drums on “Reunion.”
By contrast, Grizzly Bear started the night in full Technicolor splendor, reeling off sprawling songs (“Two Weeks”) that rang out loud and clear over an audience mouthing the words right back at the band.James Reed can be reached at email@example.com. Follow him on Twitter @GlobeJamesReed.