The duo, who have made beatboxer Gael Rakotondrabe a permanent member of their group, will play at the Pearl Street Ballroom in Northampton Thursday night at 8:30 p.m.

The pair is fresh off the release of its fourth album, “Grey Oceans,” their first studio work since 2007’s “The Adventures of Ghosthorse and Stillborn.”

Dreamlike and ethereal, CocoRosie’s material consists of often sleepy, weaving synth lines with haunting, swooning vocals from sister Sierra and overdubbed, hip-hop-styled bursts from Bianca, better known as Coco.

The combination and contrast create something unbelievably unique in today’s oft-homogeneous world of lo-fi indie music. Often sampling from children’s toys, broken phones and music boxes, the group’s unorthodox approach fashion for them an avant-garde, almost Lynchian aesthetic. CocoRosie is meant to be weird, but to them, weird is beautiful and beautiful is weird.

The sisters were raised in and out of the Native American Church, and this is often evident in their style of dress. The two will do anything from war paint and feathers to Chicago Bulls jerseys, and anything in between.

Often gloomy and melancholy, some of the pair’s work, such as that found on their 2003 debut, “La Maison de Mon Reve,” is evocative of a grey fall day with the first frost of the year nipping at your skin. It tugs, it croons and it juxtaposes Coco’s squeaky singsong rhymes with Rosie’s riveting call.

CocoRosie’s 2005 release “Noah’s Ark” is a more elaborate production, opening with the anthemic “K-Hole,” which deals with spirituality and repentance. With a dreamy synth line and beatboxed percussion, Coco sets a striking tone for the album. The work then transitions to “Beautiful Boyz” which lets Rosie rip into her deepest, most intense operatic range.

CocoRosie is nothing if not eclectic and varied. They command a wide range of abilities, as their distinct, separate styles make for a unique hybrid of electronic folk and l’opera Francais.

In performance, look for emphasis on their newest work, “Grey Oceans,” which they are currently promoting.
The album, which was released in May, incorporates many of the same harmonies and dynamics as their earlier work, but features more emphasis on the harp and relies less on the backbone of garbled synth the duo traditionally relies on. The opening track “Trinity’s Crying” features a livelier synth than much of the pair’s work, with an eerie, almost out of place conflict between synth and the sleepy folk of the harp.

One clear winner is the third track, “Hopscotch,” which opens with Coco chanting about the children’s game before shifting to a much deeper, more robust synth line than the duo features with Rosie enchantingly crowing almost unintelligible notes. The whimsical piano is a welcome departure from the pair’s more familiar, sleepy whir.

Ready or not, CocoRosie will bring its blend of weirdness, eccentricity and overwhelming creativity to Pearl Street tonight.

Sam Butterfield can be reached at [email protected].