Nick Thorburn of Islands performed in an intimate seated show at the Black Cat on Wednesday. (Josh Sisk/For The Washington Post)

“This is weird, right?” asked Islands leader Nick Thorburn from the stage of the Black Cat on Wednesday night. He surveyed the tables and chairs set up across floor of the main room — which recast the venerated indie rock club as an off-kilter martini lounge — and allowed a cracked grin to spread across his face.

The Canadian band thrives on the off-kilter, and its excellent set underscored both Thorburn’s eccentricities and his enormous songwriting gifts.

The majority of the hour-plus performance was dedicated to “A Sleep & A Forgetting,” Islands’ haunting and spare new album, which inhabits a world where dreams, mental breakdown and regret are fundamental to existence. Thorburn and Geordie Gordon (who both played keyboards and guitar) led the quartet through a stirring recitation of the tracks, hitting high points on such spectral songs as “Oh Maria” and “This Is Not A Song,” where it was possible to believe they were poignantly brokenhearted lounge singers.

The band didn’t turn completely away from the impish, squiggly pop songs that dominated its three previous albums (and drew a near-capacity audience). Thorburn eventually asked the crowd to push forward — and kick over the tables and chairs if they felt like it.

The Black Cat suddenly returned to its old self, and Islands responded with a couple of older tunes (including 2006’s “Don’t Call Me Whitney, Bobby,” offered as a backhanded tribute) and the new “Hallways,” cast as an infectious, barrelhouse-piano stomp.

Ultimately, the show confirmed that Thorburn and Islands remain a vital creative force, wandering along the pop music margins, searching for ways to keep their pop melodies as genuinely weird as possible.

— Patrick Foster