Mumbai, Jun 26 (IANS): Bollywood playback singer Sunidhi Chauhan says the "Main badhiya tu bhi badhiya" song for "Sanju" captures the era of retro music, and that it was tough for her to get the tone right. Its composers Rohan-Rohan say actor Ranbir Kapoor was quite involved in the making of the song.

Sunidhi told IANS: "My voice is different. I do not have that nasal voice. So I found it little difficult to sing, but that was the challenge I took."

Composers Rohan-Rohan -- comprising Rohan Gokhale and Rohan Pradhan -- who have worked in the Marathi film industry, have made their Bollywood debut with the song "Badhiya". While working for director Rajkumar Hirani was a dream come true for them, they were impressed by the movie's lead actor Ranbir's involvement.

"He used to be with us during the studio session at times, just to hear the song... how it is growing. If we were changing anything of the lyrics or a tune, he would listen to it and respond. He was quite involved and liked the song," Rohan Gokhale said.

Gokhale said when Pradhan and he got a call for the song for "Sanju" - a film on the life of actor Sanjay Dutt -- they were silent for 30 seconds as the fact that they were to work for Hirani didn't sink in.

"Who does not want to work with a legend like him? It is such a huge film and the song that we composed is very different. We got a chance to try something different," he said.

The brief was that a song is playing in cafe while the lead character is lip-syncing the song to prove to his father that he knows how to do it.

"We did our research work to find out, what kind of songs used to play in that era. Yes, it was retro, but what kind of retro song, how the sound should be... We followed the work of Sachin Dev Barman, Shankar Jaikishan and Jaidevji among others. So, we wanted the song to have that old world charm and little quirk," Gokhale said.

Rohan-Rohan have earlier composed songs for National Award winning film "Ventilator", which was produced by Bollywood star Priyanka Chopra. They also composed songs for Madhuri Dixit's first Marathi movie "Bucket List".

"I think we are fortunate to meet right people at the right time... People who liked our music and took us to the next level. The fact is, music connects people. As composers, if what we are creating touches people, we are doing it right," he said.