Mumbai, Aug 25 (IANS): The upcoming film 'Chup' will mark the debut of veteran superstar Amitabh Bachchan as a music composer, director R Balki divulged the details as the film is set to release on September 23.

The film is a romantic psychopath thriller, a thought Balki had after 'Cheeni Kum' and decided to write it much later. The poster revealing the release date was released on Thursday.

Talking about the same, Balki said "'Chup' is special for more than one reason. For me the biggest reason is it marks the official debut of Amitabh Bachchan as a music composer."

Big B and Balki have a long standing association and the superstar has worked with him in almost all of his films.

The director then revealed how the music composing debut for Big B unfolded, "Amitji saw 'Chup' and played an instinctive original melody on his piano as he relived the film. It was his way of expressing his feelings for the film, paying a tribute. This composition, his gift to the film, will be the end title track of 'Chup'. I don't think there can be an artist whose sensitivity can beat Bachchan's and 'Chup' has his touch!"

The film stars Sunny Deol, Dulquer Salmaan, Shreya Dhanwanthary and Pooja Bhatt. The original story is by R Balki, with the screenplay and dialogues co-written by R Balki, critic-turned-writer Raja Sen and Rishi Virmani.

The film has been produced by the late stock investor Rakesh Jhunjhunwala, Anil Naidu, Dr. Jayantilal Gada (PEN Studios) and Gauri Shinde.