"American Idol" was Justin Bieber's back-up plan.

Somewhere, Siobhan Magnus must be breathing a sigh of relief.

The 16-year-old who made his big breakthrough on YouTube says he planned trying out for "American Idol" if his web effort failed to pay off.

If so he would have been up against Siobhan and Crystal Bowersox and god only knows what would have happened!

"Me and my mom used to watch [the show] when I was little and we were like, 'I could get on there, you know.'

Instead, as the world and its mother knows, Justin posted videos of himself on YouTube and was discovered by Usher.

The rest, as they say, is history.

"When I turned 16, I might have went and tried out, but this was faster," he says.

Bieber of course was one of the stars of the show Wednesday night when he performed during the "Idol Gives Back" special which raised some $15 million.