Pop star Justin Bieber is documenting his worldwide Believe Tour by writing and recording a new song in every city he visits.

The Boyfriend hitmaker embarked on his global trek last September (12) and has already played concerts in New York, Los Angeles and London, ahead of scheduled stops in the Middle East and Africa in May (13).

Now his manager Scooter Braun has revealed the 19-year-old singer is keeping busy during his down time by creating new tracks inspired by his travels.

Braun tells MTV News, "Well, I don't ever disclose what our plans are, but I will say this: he's been writing one to two songs a day for the entire tour and he actually labels them by the city he writes them in.

"We started calling it his 'music journal' and we're talking about what should come next musically. And I think creatively he just wants to share all his thoughts through music."

During his April (13) stop in Norway, Bieber had fans talking when he was photographed with his on/off girlfriend Selena Gomez - and Braun teases, "The Oslo song, you'll have to see. Norway was an incredibly inspirational place. So you'll have to see."

Bieber previously described his music journals in a series of posts on Twitter.com, revealing he wants the songs to tell the real story behind his tumultuous world tour, writing, "Thinking about putting out my music journals from the road... Music journals = let the music do the talking."

The star's tour has been fraught with drama including a hospitalisation and a fight with a photographer in London in March (13), and a police raid on his tour bus in Sweden on Wednesday (25Apr13) allegedly turned up a stash of drugs.