Los Angeles: Grammy-winner Sam Smith has revealed he penned "Writing's On The Wall", the theme song for the 24th James Bond film "Spectre", in just 20 minutes.
He has co-written the track with fellow Grammy-winner Jimmy Napes. Smith will be the first British solo male vocalist to sing over the opening credits since Tom Jones in 1965.
"I'm so relieved to actually talk about this, this has been a top secret mission of my own. I got called into the office with (producer) Barbara Broccoli and (director) Sam Mendes and they gave me the script, I read the script... They said, 'Have a go at the song.'
"It's the quickest I've ever written a song - it took 20 minutes - and they loved it. I love the song so much," he told on BBC Radio 1.
The 23-year-old singer said recording the song is one of the highlights of his career.
While announcing his involvement with "Spectre" in an Instagram post, he wrote, "I am honoured to finally announce that I will be singing the next Bond theme song.
"I am so excited to be a part of this iconic British legacy and join an incredible line up of some of my biggest musical inspirations. I hope you all enjoy the song as much as I enjoyed making it."
Smith had been the long-running favourite but had denied any involvement and even pointed the finger at Ellie Goulding, who had been another top choice alongside Ed Sheeran.
The singer follows on the heels of Adele, who sang the theme for the last Bond movie "Skyfall", winning an Oscar for her efforts, and keep Bond theme song firmly in the UK after a lengthy spell across the Atlantic. Commenting on the announcement, the film's producers Michael G Wilson and Barbara Broccoli, said, "Sam and Jimmy have written the most inspirational song for Spectre and with Sam's extraordinary vocal performance, 'Writing's On The Wall' will surely be considered one of the greatest Bond songs of all time."
The song, released by Capitol Records, will debut and be available to purchase and stream on September 25.
Mendes returns to direct "Spectre" after "Skyfall", with Daniel Craig reprising his role as 007 for the fourth time.
The screenplay is by John Logan and Neal Purvis and Robert Wade and Jez Butterworth, with a story by John Logan and Neal Purvis and Robert Wade.
The movie is set for release in the UK on October 26, 2015, and in the US on November 6. It will hit theatres in India on November 20.