It has been flagged as the show of the year that should not be missed.

With 250 performers on stage and one of the world's top sopranos - WA's Elena Perroni - Britten’s War Requiem with WASO is a rare event that will delight.

Principal conductor Asher Fisch will be leading the show this Friday and Saturday nights at the Perth Concert Hall.

He told Liam Bartlett on 6PR Mornings the anti-war piece is the most famous of renowned composer Benjamin Britten's works, first performed in 1962.

"Surprisingly it is in disguise also an anti-religion establishment piece, which is quite shocking," he said.

"When Britten first performed it they used to perform with three conductors."

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