Later, after his arrest, Vadim Semin was at a loss to explain his actions. It was a perfectly ordinary concert, perhaps not as big or as successful as he’d have liked, but the sort of charity engagement he’d fulfilled dozens of times. 

Going to a Bob Dylan gig these days requires a certain sort of mindset. Worship, obviously, but also a readiness not to see or hear anything pleasant for two hours. The greatest fan of Dylan I have ever met wears earplugs during his concerts. And Dyl…