Phosphorescent, ICA, London

"Sometimes I can play too rough," Matthew Houck croons on "Tell Me Baby (Have You Had Enough)". "Tell me baby have I gone too far?" He pleads. There's scant rough stuff tonight, and Houck's pugnacious Brooklyn-based outfit are refreshingly, delightfully "far out".

This shaggy six-piece sport the mandatory Americana garb: fashionably rumpled beard, tattered shirt, battered headwear; and with their swirling, heads-down plucking, they come across like a mid-Seventies hard-rock act on The Old Grey Whistle Test. When they twang together particularly heavily they resemble Lynyrd Skynyrd without, thankfully, the dismal bluster. In fact, this sublime, joyous gig quite often feels like a Cajun hoedown in Lafayette; it brims with twisted, Bonnie Prince Billy-style country-rock without the deep misanthropy, but with a similar glint of smuttiness – "Let your ass out on the floor," Houck implores his lover on the weary, peripatetic ballad "We'll Be Here Soon". And in "Nothing Was Stolen (Love Me Foolish)" they possess a love ballad to rival Neil Young's "Harvest Moon".

The 30-year-old Houck, founder member, lyricist and leading man of the sextet, has been working under the moniker Phosphorescent since 2003. His previous releases – including Pride and To Willie (a tribute to Houck's hero Willie Nelson) – have been lauded by influential tastemakers such as Stylus magazine and Pitchfork. But it's now, with his latest dazzling record, Here's to Taking It Easy (Tho the Jaws of This World Wish Only to Grab Hold of Your Sweet Ass), that this rake-thin balladeer has finally arrived.

Houck and his hairy cohorts appear ready for it – ready for all of it – playing this intimate venue like it's the Albert Hall; with bravado and precociousness. Swirling, cinematic and plaintive folk-rock, blessed with Houck's pained, gorgeously cracked vocals, which are tailor-made for country-and-western laments.

The Alabama-born Houck, with his Art Garfunkel hair, resembles a sociology teacher who took too much acid at college and you sense he enjoys a diet of hard living. In fact, this lot, beers by their side, reassuringly appear to shun clean-living – they booze: "I know I spend most of my life in these bars" on "Tell Me Baby"; and they lust: "Out bodies we're like hotwires down on a beach in Mexico", on the epic "Mermaid Parade" about a former lover. The track is Houck's crowning, Springsteen-like moment tonight, with the sumptuously bereft lyric "I came back to this city/ And you stayed home in LA/ And our two years of marriage/ In two short weeks/ Somehow just slipped away".

The performance is blessed with a sprinkling of Willie Nelson covers, including "Too Sick to Pray" and "It's Not Supposed to Be That Way", but it must be comforting to know, for definite, that the "new album" is the "best album" and the latest ones are the strongest tracks. Sensational country-rock songs redolent of the best: Crazy Horse, The Band, Tom Petty and Jackson Browne.

Phosphorescent should be huge soon; they probably require a catchy hit on a US TV series or on a cult film to nail it for them. But their grandiose blend of despair and beauty, of the Southern gothic and New York freakery and West Coast drifting is sure to win out. True to their name, they were persistently bright tonight. I wore a silly grin throughout.