The Knife, a brother-sister duo made up of Karin Dreijer Andersson and Olof Dreijer, are responsible for some of the most beguiling, original pop sounds in years. Thanks to the 2006 Silent Shout album, José González's "Heartbeats" cover, and the group's unconventional live performances, they have created a fascinating niche at the intersection of performance art and electronic pop music. Perhaps the only comparable, large scale artist would be Björk–with whom they do share a predilection for odd vowel sounds and amorphous song structures. Shaking the Habitual goes further out than most pop records ever will, with creaking, hypnotic experiments like "Fracking Fluid Injection" spiraling into nearly 10 minutes of dream state paralysis. "Old Dreams Waiting to Be Realized" is nearly double that length with its ghostly creaks and waves of sound. The booming dark noir of "Ready to Lose" calls to mind the electronic despair of Marianne Faithfull's Broken English while "Without You My Life Would Be Boring" is a deep, cyclical Afro-electro-funk groove with Anderson unveiling a twisted and beautiful vocal turn. If it's ambitious, uncompromising rhythm and sound you're after, The Knife continue to cut deep.