When it comes to young people in music in 2017, Ed Sheeran seems the perfect place to start. The 26-year-old star is fresh from a Glastonbury headline set and two million sales into an album campaign that seems as if it may last forever. It’s fair to say he has dominated 2017.

But it wasn’t always this way. Once upon a time, from 2008-2009 to be exact, Sheeran was enrolled on the Artist Development course at the London branch of ...