Andrew Lloyd Webber's TV talent show How Do You Solve A Problem Like Maria? is demeaning to contestants, theatre director Sir Trevor Nunn has said.
Contestants include Simona Armstrong (left) and Leanne Dobinson (right)
"What these reality programmes more or less rely on is the viewing public being witness to distress," Sir Trevor told The Times newspaper.
"That is absolutely not how casting proceeds in the theatre."
The BBC programme sees 10 contestants compete for the lead role in a West End production of The Sound of Music.
The mixture of classically trained performers and amateurs must perform for a panel of judges, led by Lord Lloyd-Webber.
Viewers can then vote for their favourite, with the least popular contestant thrown off the show each week.
But Sir Trevor, who was director of the National Theatre from 1998-2003, said he found the programme distasteful.
Sir Trevor Nunn was involved with the new Sound of Music production
He told The Times the normal audition process has "more to do with the respect of people" than "a group of people behind a table saying 'you're out'".
The director, who has worked with Lord Lloyd-Webber on productions of Cats and Starlight Express, had an early role in planning the new production of The Sound of Music.
But he left before the TV show began. "It was not a route I wanted to follow," he said.
The director is currently working on a new stage adaptation of George Gershwin's Porgy and Bess.
He will also direct Sir Ian McKellen in a Royal Shakespeare Company production of King Lear in 2007.
The Sound of Music debuts at the London Palladium on 3 November 2006, with the competition winner playing the role of Maria.
The character was made famous by Julie Andrews in the 1965 film version of the musical, which won five Oscars.