The Biophilia live show at Harpa, Reykjavik is another cog in the complex wheel that makes up Björk’s eighth album, which is not simply a collection of nice songs, but a concept record about nature, a series of educational apps and a showcase for its specially created instruments. The performance is, however, where it all comes to fruition, with the extensive thinking behind it distilled into the joy of putting on a show. Björk is the star attraction of the Iceland Airwaves annual music festival, and there’s a particular magic at seeing her not only perform in her home town, but her 20-strong girls’ choir, too, who add a dance