Jaws

For the film of Peter Benchley's novel, three mechanical sharks were built. The crew named them all Bruce, after Steven Spielberg's lawyer.

They had been tested in fresh water. The film was shot at sea.

The first time Bruce went into the salt water of Nantucket Sound, he sank. Saltwater then went to work on him from both directions — corroding the exterior, seeping into the pneumatic hoses that operated him — and the shark became close to unusable.

A film about a shark, with no working shark.

Spielberg had a schedule, a budget and a monster that would not perform. So he shot around it.

Yellow barrels moving across the surface. A camera low in the water at swimmer's eye level. An empty horizon. And John Williams's two notes, doing the work the animatronic could not.

In a film named after it, the shark appears on screen for about four minutes.

The result is the principle every horror film has used since: the thing you are not shown is worse than the thing you are. It was not an artistic choice made in advance. It was damage control by a young director whose equipment had failed.

Released in the summer of 1975 into a wide simultaneous release backed by national television advertising — then an unusual approach. It worked so completely that it became the template, and every summer blockbuster since is descended from it.

The film won three Academy Awards: Best Film Editing, Best Sound, and Best Original Score for John Williams, whose two-note theme is among the most recognised pieces of film music ever written.