Though he is not done with his 2013 Believe world tour, Justin Bieber is already working on new music and revealed who he is collaborating with on the new tracks.  

He uploaded on Aug. 3 an Instagram photo of him in the studio with Big Sean. Details of the music were not revealed but the two do have musical chemistry, proven in their collaboration for 2012's As Long as You Love Me. The track was included on Bieber's 2012 album Believe.

The artists were in the recording studio a day after Big Sean released the music video for Fire featuring Miley Cyrus. The Detroit native is also preparing for the Aug. 27 release of his sophomore record Hall of Fame, the follow-up to his 2011 debut record Finally Famous.

Bieber on Aug. 16 was in the recording studio with Future, also evident through an Instagram photo the 19-year-old uploaded. The Atlanta, Ga., hip-hop artist, who is signed to Epic Records, A1 Recordings and his own label Freebandz, will release his album titled Honest on Nov. 26. The record will be the follow up to Pluto, his 2012 album. He premiered the new album's lead single, also titled Honest, earlier in Augst via Ustream.

The Instagram photo leaves fans wondering if the collaboration is for Bieber's new album or Future's. Regardless, Future is no stranger to pop music: he contributed writing and production to girlfriend Ciara's latest, self-titled album. It is unclear what other hip-hop collaborators will be on the album but Bieber but earlier in the year, he rapped alongside Juicy J about his "Lolly" and was seen hanging out with R. Kelly, which could lead to a collaboration in the future. Bieber also spent time in Miami with Jay Z.

Though not much of a live collaboration, Bieber released a new song on Aug. 16 titled Slave to the Rhythm featuring vocals by the King of Pop Michael Jackson. Slave to the Rhythm uses a remixed track of Jackson's song, which was released shortly after his death in 2009. Bieber touched up the track with his vocals and layering up Jackson's refrain. On the day of the song's release Bieber tweeted a spliced black and white image of him and Jackson on stage with the message, "Excited for what is to come. MJ set the bar. Not only for music but for being an entertainer and how u treat the fans. Wish he was here..."

Bieber has been busy at work on his new album and from his tweets, some predict his new album will be titled Greatness.

"@scooterbraun love u too man. great talk. nothing is stopping us. #greatness #BELIEVE" he wrote to his manager in July.