For those who remember American Idol's fifth season, Katherine McPhee's opening number in Smash was a bit like déjà vu.

In the premiere of the new NBC musical series, the former Idol semifinalist sings Somewhere Over The Rainbow--just like she did for Simon Cowell and the gang in 2006.

A lot has happened since McPhee was a 22-year-old girl from Sherman Oaks, Calif., just trying to make it as a singer.  In February 2011, she was cast in the pilot for Smash a musical series about a young actress' struggle in the world of Broadway. It premiered Monday night.

In the opening scene, Karen Cartwright--played by McPhee--belts out the famous Wizard of Oz tune in an audition for a play, only to be cut off by crass casting directors. She rushes out of the room, clearly upset.

McPhee's real-life performance of Somewhere Over the Rainbow several years before went quite differently.

This is what I've been waiting for. This is the best vocal of the season, exclaimed Randy Jackson over the audience's thunderous applause.

Cowell, the notoriously harsh critic, lavished McPhee with praise as well. I'm not just saying this because I chose the song, but that was the single best performance of the competition today.

What do you think of the two performances? Take a look at the videos below.

Note: the below video can only be viewed once.