‘Go on, Dougie,’ the man beside me shouted. His silver and blue lapel pin twinkled in the wan light of Screen 7 at Cineworld in Edinburgh. To my left, a woman beat her foot as Dougie MacLean shuffled with his guitar across the makeshift stage at the launch of Yes Scotland last Friday. In the front row, Nicola Sturgeon, Scotland’s deputy first minister sang along to ‘Caledonia’; Alex Salmond grew lachrymose, or at least appeared to in the footage broadcast on the evening news.