"Initially, I was very reluctant. I even told my director Rakesh Sarang that my voice is only suited to give playback to buffaloes," Nana told.
However, when music director Lalit Pandit of the famed Jatin-Lalit duo persisted, Nana agreed to sing. The situation and his role of a bored Mumbai taxi-driver demanded it and so the actor decided to give it his best try.
It has been more than a decade since Nana, who is playing the lead role in the movie, has lent his voice to a song. His first song was "Ek machar aadmi ko hijda bana deta hai", which the actor describes as a "prosey -talking song".
The latest rap number will be a full-fledged lyrical composition and for Nana "it was a satisfying experience to sing it".
When told that singers like Lata Mangeshkar or Mohammed Rafi could wrap up a complete song within an hour, Nan folded his hands and said: "They are gods, I am a devil, there's not the remotest comparison with them."
But he revealed that the song was recorded in 30 minutes flat. How come?
"Well, probably the music director found that he could do nothing more to improve on my voice or singing style!" he joked.
As for rehearsals before the recording, Nana did none.
"Lalit is a dear friend and he can make anything sing, even a cow. Perhaps, that's why I could succeed in this experiment!"
The "Ab Tak Chhappan" star who indulges in self-criticism has apparently earned praise for his efforts from the music director.
"He is a natural singer. We had loads of fun recording this number. I am sure youngsters will love it," said Lalit.
Nana confessed that he loves songs and singing, but until recently his singing skills were restricted to the bathroom.
"These days in Mumbai, with flats crammed so close to each other, one must be careful about bathroom singing. You never know who is taking a bath in the opposite flat's bathroom. Belting out a wrong 'number' could have disastrous results," he guffawed.
However, he is quite pleased that his film unit liked the song. What about family, friends?
"Nobody knows and I am not telling them. Let them find out after the music album is released. I am not taking any risk now, please," he said, lowering his voice.
The song has lyrics by Sajid Farhaad and was recorded recently in the Empire Studio.
Apart from Patekar, the movie cast includes Rimi Sen, Muzamil Ibrahim, Ali Asgar, Satish Shah and Sada.
With this, Nana joins the select club of actors like Amitabh Bachchan, Aamir Khan and Sanjay Dutt, who occasionally indulge in playback singing.