CocoRosie remain a distinctly polarising musical proposition. Put simply: You either love or hate sisters Bianca and Sierra Casady's witches' brew of haunted freak-folk, spectral samples and wilful whimsy, and Grey Oceans will not be converting the naysayers any time soon.

The case for the prosecution sees the Casadys' muse as contrived and pretentious, and you need an iron constitution indeed to survive the helium vocals, tinkling xylophone and gamelan and kooky train whistles of "The Moon Asked The Crow" without feeling mildly icky. Mostly, though, they come up trumps because at the heart of their contrary art-pop beats a rare and fierce beauty. The gorgeous, stately piano, shuffling hip-hop beats and eerie Joanna Newsom-like flourishes of "Lemonade" are simply delicious, while the fractured "Fairy Paradise" marries tremulous, insatiable vocals to thumping rave beats with an élan rarely found in anybody but Björk.

Tellingly, Grey Oceans' best moment is its weirdest and most audacious: the hypnotic "Hopscotch," which welds juddering junglist beats and shimmering phantom vocals to, of all things, a honky-tonk barrel organ. The musical mainstream will doubtless continue to hold CocoRosie at arms length but these quixotic sisters' outré sonic concoctions remain laudable and profoundly moving.