Many years ago, when I was struggling to make a living as an actor–singer in England, I spent six months in the chorus at the London Palladium, in a show breezily titled Let Yourself Go, whose star was former Goon Harry Secombe. It was hard work: two performances nightly, plus a matinee on Saturday. Years later, I realised that this demanding regimen was inherited from the days of music hall, when it was morphing into what was called variety, of which Let Yourself Go was a latter-day example.