Much of CocoRosie's allure has always lain in the pie-eyed childlike wonder of their lyrics and vocal delivery, along with a playful curation of disparate samples, electronic beatmaking and unconventional instrumentation and arrangements.

No sound is seemingly safe for the duo, who have applied toyshop animals, field recordings, bicycle bells, music boxes, synths, lo-fi production values, an endless array of tools, tricks and effects to loop, manipulate, twist and distort voices as well as a whole heap of other musical curiosities in their time recording together.

During recent years and on their last few albums, the sisters - Bianca 'Coco' and Sierra 'Rosie' Casady - have developed and refined their sound, producing more accessible and melodic music, albeit one that is still held together by an unpredictable and other-wordly bond.

That CocoRosie share such qualities with artists like Bjork, múm, Camille and Feist is not so unusual, given they share a producer. The Icelandic go-to engineer, composer and musician Valgeir Sigurðsson took production credits on the duo's exceptional 2007 album The Adventures of Ghosthorse and Stillborn and returned again to oversee their latest collection of songs, Tales Of A GrassWidow.

The Casady sisters are no less dramatic or fantastical on this new album. It's just, well, they sound like more cultivated and fully-fledged artists than ever before, and have produced tracks that have memorable and powerful verses, choruses and clear structures as demonstrated on the wonderfully descriptive opener 'Welcome To The Afterlife' and follow-up 'Tears For Animals' which features the soft vocals of Antony Hegarty over deliciously simple electronica, echoed by a hypnotic harmonised repetition of "Do you have love for humankind?"

Hegarty once wrote of the duo, "(They) paint pictures of lost children across a broken land, feral, elemental spirits who roam the dreamscapes of our world, naming perpetrators, painting their memories, recovering and reclaiming power." I'm not sure that I can put it any better, and certainly on Tales Of A GrassWidow, the almost unbelievable set of circumstances and experiences that have shaped CocoRosie’s lives and musical styles to date are as influential as they have always been - eccentric, diverse, challenging and beautiful.

'Child Bride', 'Broken Chariot' and 'Harmless Monster' contribute perfectly to the kaleidoscope that is the new album - whispering and piercing vocals, field samples, haunting piano and synth lines, drum patterns, harp and flute accompaniment, choral backings and eerie howls all litter the road less travelled by the duo.

The lyrical delivery on tracks like 'End of Time', the brief beauty of 'Harmless Monster' and single 'Gravediggress' epitomises the strange and kooky sonic world that CocoRosie inhabit, except that as with artists like The Knife, the artist's words are also a vehicle for commentary on a wide variety of issues, notably including social injustices, feminism and the advance of humanity.

Closing tracks 'Villain' and 'Poison' sum up Tales Of A GrassWidow nicely. Both are unlike any other track on the album and are hugely distinctive, via what sounds like a harpsichord clashing with a searing echoing vocal and reverse samples on the former, and a slow burning tribal beat with a late surprise on the latter. Surprising if you’re new to CocoRosie, unsurprisingly extraordinary if you’re already a fan.