Simon Cowell Stops by I CAN'T SING! Rehearsals for Some Impromptu Judging

As if playing a parody version Simon Cowell wasn't enough for Olivier winner Nigel Harman, he also had to perform in front of the real-life legendary X FACTOR judge - with absolutely no warning.

According to The Evening Standard, Cowell recently crashed a rehearsal for I CAN'T SING!, the upcoming West End musical spoof of the hit singing competition show - just as Harman was in the middle of a performance.

A source told the publication: "It was a little bit like Nigel was auditioning for The X Factor, with Simon sat right in front of him...It was really awkward at first because obviously the musical is a parody of The X Factor and Simon. But he found the rehearsals really funny and thought Nigel did a great job. He even took him aside and gave him some advice."

I CAN'T SING! also features Victoria Elliot and Alex Knight as the other judges, Cynthia Erivo (recent Evening Standard Award nominee for The Color Purple) and Alan Morrissey as lovestruck contestants Chenice and Max. Simon Bailey will play the overly affectionate X Factor host Liam O'Deary, with Billy Carter as Executive Producer and Simon's right hand man, Gerard Smalls.

I CAN'T SING! begins previews 27 Feb at the London Palladium.

Written by Harry Hill and Steve Brown, the brand new comedy features 19 original songs and goes behind the microphone and under the judges' desk to reveal the (not necessarily accurate) story of heartache and laughter that keeps millions tuning in to the X Factor every week.

Directed by Sean Foley (The Play What I Wrote; The Ladykillers) with choreography by Kate Prince (Into the Hoods; Some Like it Hip Hop) and set design by Es Devlin (designer for London 2012 Olympic Closing Ceremony; Take That stadium tour).

Check out a sneak peek of the musical's title song below:

Photo Courtesy of Fox