Simon Reynolds’s first book in eight years is a celebration of music that feels like a taste of tomorrow. Sounds that prefigure pop music’s future -- the vanguard genres and heroic innovators whose discoveries eventually get accepted by the wider mass audience. But it’s also about the way music can stir anticipation for a thrillingly transformed world just around the corner: a future that might be utopian or dystopian, but at least will be radically changed and exhilaratingly other.