Justin Bieber's show with Bryan Adams was last-minute

Justin Bieber's recent performance with Bryan Adams last month (Sep15) was hastily put together as they did not decide to collaborate until minutes before the pop star went on stage.

Last month (Sep15), the pair teamed up for an unlikely collaboration at Universal Music Group's Universal Inside conference in Berlin, Germany.

They performed an acoustic version of Justin's hit track Baby, with Bryan playing the guitar and singing along.

The rocker has now opened up about the show and revealed he approached Justin about the duet just minutes before show time.

"Our record company is Universal and they had a conference in Berlin," Bryan explains to the Sydney Daily Telegraph.

"He was playing on it and I was playing on it and I said to him just before he went on 'Do you want to do a song together?' and he said 'sure'. He seems great."

Bryan goes on to express his admiration for the young pop star and urge him to stay strong despite criticism of his bad boy antics.

"If you are going to be in the limelight you have to be a bit thick-skinned," Bryan adds. "You're going to get it no matter what the format so just go with it, have a laugh, keep doing what you are doing, keep your chin up and that's it."

Justin has enjoyed a successful return to the charts in recent weeks following several years in the pop wilderness.

His comeback single What Do You Mean?, which is rumoured to be about his ex-girlfriend Selena Gomez, landed him number ones around the world.

It precedes his upcoming currently untitled fourth studio album. The record is set to be released in November (15), the same week his pop rivals One Direction unleash their latest offering.