The second volume of Cocteau Twins’ singles anthology covers the band’s final years, which yielded some of the most gorgeous music of their career. “Bluebeard (Acoustic Version),” stripped to just guitar and rhythm box, fully reveals the astonishing agility of Elizabeth Fraser’s voice; the swirling “Feet Like Fins” teases at the trip-hop direction they never got to pursue. And the dubbed-out “Cherry-Coloured Funk” version turns the Heaven or Las Vegas opener blissfully woozy, making good on the ambient potential at the heart of their sound.