Film director Sriram Raghavan, whose new movie AndhaDhun is being eagerly anticipated in the Hindi cinema circuit, says writing a thriller story is very challenging for a film which demands constant audience engagement.

The movie, releasing on Friday, features Ayushmann Khurrana, Tabu and Radhika Apte.

Raghavan said: “We have written this story with a group of writers. So when one person came up with an element, others were reacting to that as an audience to find out if it was thrilling enough to feel engaged and worth enough to incorporate in the story. Writing a thriller is quite challenging, especially for a film because we have to keep the audience engaged constantly.”

The story has been written by Arijit Biswas, Pooja Ladha Surti, Yogesh Chandekar along with Raghavan.

AndhaDhun revolves around a visually challenged piano player, played by Ayushmann, who gets into a mysterious situation. It is about how a series of incidents get unfolded afterwards, bringing about significant changes in his life.

While Raghavan was quite sure about roping in Tabu for the movie, he was initially on the lookout for a new face to play the male protagonist.

“Just after finishing the story, I narrated it to Tabu and asked if she is interested because I so wanted to cast her in the film. Thankfully, she agreed. But the shooting of the film started much later because I wanted to cast someone who is ready to invest time to learn the piano.

“Though I auditioned three actors, none of them were fitting my kind. Ayushmann took two months to learn the instrument,” said Raghavan, who has earlier made films like Badlapur, Agent Vinod and Johnny Gaddaar.

Why was it important for an actor to learn the piano just for a film?

“Authenticity, I guess… In the film, there is a 90-second musical piece that Ayushamann is playing in the beginning. That establishes the fact that he is a piano player who is visually challenged. Even the close-ups of fingers can depict emotions that I do not want a body double to do. The tune on the piano itself is an element of the story,” Raghavan said.

The shooting of the film took place in Pune. What was the toughest part of shooting the film?

“Firstly, getting a house with an old world charm that we found in Pune was a little difficult. We shot the film in a house of a middle-aged couple. During the shooting, we had to uproot the family to a hotel. The toughest part was after finishing the shoot when we realised that some patchwork needed to be done and therefore the house,” he recounted.

Raghavan says convincing the members of the house to allow the film’s crew to shoot there again was tough.

“In shooting, we tend to turn a place upside down. So it’s obvious for any house owner not to allow people to do that again. Thankfully, the family was very cooperative and we finished the shoot perfectly,” he said.