Katy Perry's No Simon Cowell for 'American Idol' Reboot's First Disaster Audition

The "American Idol" reboot saw its first train wreck of an audition this weekend, but there was no real Simon Cowell to be found among any of the judges ... try as Katy Perry did.

A woman named Koby -- who's a theater performer -- was the first 'no' Sunday night on the premiere of the new 'AI,' with Katy, Lionel Richie and Luke Bryan in the judges' chairs.

No offense to the aspiring singer, but her audition was terrible -- and it was the first opportunity for the judges to show their true colors ... and to see if anyone would fill in Cowell's "mean judge" shoes.

Katy did kinda take a crack at it, but she's no Simon Cowell ... as you can see from her feedback. Katy is direct and slightly harsh, telling Koby "You're not a pop star. It's not right." But aside from that, the criticism was relatively mild compared to the good ol' days.

Lionel and Luke also did their best Randy and Paula impressions, but it ain't the real McCoy.