The documentary’s most striking moment arrives when a camcorder lands on Jackson’s notebook in 1989, the first verse of “Rhythm Nation” scribbled down on an unlined page, proof of how something righteous and colossal can start with a few messy pen strokes.

A staff member said: “When Gillian goes on holiday, she looks at every single page proof on her sun lounger, on a laptop, and then phones in changes.”

Of that “not particularly valuable” page proof, he says: “Where would you even start the bidding on something like that? At least $100,000? It’s an open-ended question.”

Imagine reading the same 100,000 words three or four times, from one draft, and then page proof, to the next.

Using an intercom, Meg would buzz one of us to come into her office, to pick up a page proof and occasionally to ask us what we thought about a particular article.