The C90 cassette unspooling on the sleeve makes an apt motif for an album that is both a tribute to Scottish pop and a personal testimony from Caledonia’s reigning folk queen. Not that there’s much folk involved; most of the songs Karine Polwart interprets here are from the mainstream, drawn from a live show in turn inspired by an Edinburgh exhibition, Rip It Up, celebrating Scotland’s distinctive contribution to British pop. Big Country’s Chance, for example, was an air-punching anthem for a teenage Polwart in smalltown Stirlingshire, though it’s here transformed into a meditation on domestic abuse and an abandoned young mother.Polwart works similar reconstructions on the likes of Deacon Blue, the Blue Nile and John Martyn. Strawberry Switchblade’s Since Yesterday morphs from bubblegum romance into a commentary on Alzheimer’s – “I’m scared I’ll have to say/ That a part of you is gone since yesterday” – while the Waterboys’ rocking The Whole of the Moon gets a minimalist treatment, with deft backings of glockenspiel and clarinet from a fine band. Whatever the song, Polwart’s vocals, austere rather than exuberant, tease out underlying themes of resilience and resistance to make a compendium of small-p political pop.