For the singles from her album/educational tool/multimedia app Biophilia, Björk recruited artists as distinctive, ambitious, and rule-breaking as she is to provide remixes. Spanning newer acts like Death Grips to longtime collaborators like Matthew Herbert, Bastards gathers the most striking reworkings of Biophilia's songs. Where the album had a fittingly organic flow to its meditations on nature (human and otherwise), Bastards branches out from that concept while remaining true to its essence. These tracks aren't as lacking in parentage as the collection's title suggests, but they are notably unlike each other and the album that spawned them. "Crystalline" inspired two of the best, and most different, remixes: Omar Souleyman imbues the track with his Syrian-tinged electronics, transforming the linear vocal melody into something almost unrecognizable yet entirely natural-sounding. Meanwhile, Herbert (who contributes three remixes to Bastards) adds jagged beats that mimic the raw beauty of crystal growths. While many of these reworkings expand on Biophilia's outbursts, some of the best are also the quietest. On their version of "Mutual Core," These New Puritans largely stay out of the way of Björk's powerhouse vocals, instead dropping brass and piano in and out of the track for a more subtly dynamic approach. Elsewhere, the Slips' take on "Moon" emphasizes that song's fragility, and Alva Noto's remix of "Dark Matter" makes it all the more spectral. While not every experiment here works this well, Bastards delivers the kind of envelope-pushing expected from a Björk remix album. Diehards who have all of Biophilia's singles may not need this, but it's still a fine collection in its own right.