The 72-year-old took to his official blog to turn the clock back in time when he was hesitant to sing the song "Mere paas aao", but the film's team gave him a boost to get in front of the mic.
"It's 36 years of 'Mr. Natwarlal' and it's difficult to imagine that time has gone by so rapidly. As rapidly as we shot this film. Rakesh Kumar the director, who's son assists on 'Wazir' now, had been assistant to Prakash Mehra on 'Zanjeer'.
"But 'Mr. Natwarlal'...dear me...so many memories of the film. The songs given by Rajesh Roshan... were quite exemplary. I remember the sitting we had at his music room, where I was given the sudden news that I was to sing for the first time my own background song...'mere paas aao'...and terrified with the proposition, had battled long hours with the director and the music director that I would not do it because I simply could not. But then that is another story," Big B posted on his blog.
The film, featuring Rekha as the female lead, was directed by Rakesh Kumar and presented a perfect mix of action and romance.
Amitabh, who has been a part of the film industry for over four decades, didn't stop singing for films. He used his baritone for tracks like "Hori khele raghuveera" and "Rang barse bhige chunar wali", and also sang the national anthem for his film "Shamitabh".
The 'Shahenshah of Bollywood' is surprised that his relationship with the tunes and rhythms still continue.
"A nightmare it was. But when it got over, the eminent sound recordist Ghosh babu telling me I should sing more often, and how I had accepted that with a large pinch of salt! Not realising how years later and even now the singing continues, giving pain to all its listeners," he added.
On the professional front, the actor is prepping for "Wazir", which also stars Farhan Akhtar.