Most of the music at the London 2012 opening and closing ceremonies, rumoured to include big name performances from Coldplay and the Rolling Stones, will be pre-recorded.
It means that artists at the showpiece global event will be singing over vocal and instrumental tracks recorded in a studio.
London 2012 claims it's due to the "complexities" of staging such a show at the Olympic Stadium in Stratford, east London. The bowl-shaped stadium and the unreliable British weather are factors which have to be dealt with in staging the shows.
The Musicians' Union told The Times that the situation is "shameful", particularly coming from a nation famous for live music.
London 2012 are keeping tight-lipped about who will perform at the opening and closing ceremonies. Last week, the Noisettes told Evening Standard magazine that they are "involved".
Twitter users didn't respond kindly to the decision: