Singer Justin Bieber (L) And Model Lara Stone During The 'Fashion Rocks 2014' Concert
Justin Bieber has showed off his ribbed abs and a great physique on the cover page of a famous health magazine for men. The 21-year-old has also blasted critics who say that his pictures are photoshopped. Singer Justin Bieber (L) takes his shirt off as he and model Lara Stone introduce an act during the "Fashion Rocks 2014" concert in the Brooklyn borough of New York September 9, 2014. Reuters/Carlo Allegri

Justin Bieber and Cody Simpson are working on a new song. The two singers can be seen rehearsing a rock-pop duet in a short video. The video is taken and uploaded on the social media network by Bieber’s mother, Pattie Mallette.

“I will follow back on keek everyone who comments on this video! Excited! Remembering @codysimpson @justinbieber,” wrote the 39-year-old Canadian author and film producer in a tweet. The link of the rehearsal's video one is also provided with the tweet.

The 36-second video has gone viral, in which the two pop stars can be seen working on their new music. The song is possibly titled "I Won’t Let You Down," Inquisitr reported. Both the singers have yet to comment about the possibility of an upcoming track.

As the video begins, Simpson can be seen leading the song clip, while Bieber is visible clearly in the distance. The song seems to be a duet as Bieber takes it forward with his high pitched fine vocals.

The two pop stars had worked together earlier as well and had released a song last year in November. Their song "Home to Mama" was much appreciated by music lovers and fans alike, Inquistr reported.

While speaking with Idolator after the release of "Home to Mama," Simpson had hinted at the possibility of a few more collaborations with the "Baby" hit maker. He had revealed during the interview that they had written about 13 songs together.

It is highly speculated that the new song is written about Bieber's ex-girlfriend Selena Gomez, with whom he had separated a few months ago. "The stuff I have with Justin is all very much based around romance and women,” Simpson said in an interview with Idolator. “We were both in a place where we both had broken up with our girls, and we wanted to get all of that out.”

Both, the 20-year-old Bieber and 19-year-old Simpson, were discovered through their respective YouTube videos. While Bieber was discovered by his current manager Scooter Braun, the Australian sensation was introduced to the world by Grammy-nominated record producer Shawn Campbell.

For any comment/feedback regarding this article, please email the writer at p.bhagat@ibtimes.com.au.