The last thing the world needs is another film festival. But the Ballerina Ballroom Cinema of Dreams, which took place Aug. 15-23, is something else.

On a quixotic impulse, actress Tilda Swinton launched the event in her adopted hometown of Nairn, Scotland, in order to show any movie she pleased.

This was a film festival stripped back to its barest essentials. Tickets cost $6, but anyone bringing a plate of fairy cakes was admitted free.

Her co-conspirator was Mark Cousins, with whom she recently made a film about being 8½ and falling in love with cinema. They wanted their event to capture that same sense of childlike awe, wonder and discovery.

That’s why the fest lasted 8½ days, and closed with Fellini’s “8½.”

“If we knew anyone sensible, they would have told us not to do it,” Cousins laughs.

Populist classics such as “Singin’ in the Rain” sat alongside obscure yet brilliant films about and for children, from all corners of the globe and every era — “The Boot” from Iran, “Palle Alone in the World” from Denmark, “Crows” from Poland, “The Singing Ringing Tree” from East Germany.

The Ballerina Ballroom Cinema of Dreams wasn’t really a festival at all, but a folly — a personal, self-indulgent, infectious celebration of the joy of movies. No wonder Cousins and Swinton are determined to do it again.

“We see it a bit like Brigadoon, where a little village pops up every couple of years,” he says.

The world can always use that sort of magic.