James Sandom is contemplating how things have changed since he took up the dark arts of artist management back in the late ‘90s.

“When I started in this business, there was a list of about 10 things a manager had to do,” he laughs. “If you got eight out of the 10, then you knew that, more than likely, your campaign would get off to a good start, and you could think positively about the next campaign.

That list is ...