What did the rain in singin have added to it so would show up better film?

It's likely you're referring to the iconic rain scene in the musical "Singin' in the Gene" (not "Singin'"). In this scene, the rain was enhanced in several ways to create the mesmerizing visual effect:

* Water Sprays: They used specialized water sprays to create a consistent and heavy downpour, making the rain look more dramatic.

* Added Rain: Additional rain was added using hoses and pumps to ensure enough water for Gene Kelly to splash and dance in.

* Mirrors: Mirrors were strategically placed around the set to reflect the light and create a more shimmering and vibrant rain effect.

* Lighting: The lighting was carefully designed to illuminate the rain and create a sense of magic and joy.

* Editing: The editing techniques helped to emphasize the movement and energy of the rain and Gene Kelly's dancing.

This combination of techniques made the rain scene in "Singin' in the Rain" not only visually stunning but also a testament to the creativity and technical skill of the filmmakers.