20 Things You Didn’t Know About Quantum Of Solace (2008)
3. “I Really Think You People Should Find A Better Place To Meet!”
In Paul Haggis's rewrite of the script by Neal Purvis and Robert Wade, Double-0 Seven discovered Dominic Greene, Mr White, and other representatives of the sinister Quantum organisation meeting covertly at an international diplomatic conference.
James Bond "borrowed" a device from a Quantum agent to listen in on their conversation (much like he does in the finished film), but had to keep changing the frequency because the villains were speaking in several different languages. Meanwhile, the diplomatic conference being used as a cover by Quantum would have continued in the background.
Marc Forster liked the idea, but felt that it was not visual enough for a Bond film. He therefore changed it to take place at the floating opera house in Bregenz - the largest outdoor floating stage in Europe - on the shores of Lake Constance during the Bregenz Festival, featuring Philipp Himmelmann's interpretation of Giacomo Puccini's Tosca based on a libretto by Luigi Illica and Giuseppe Giacosa.
The production hired 1,500 extras to feature in the sequence and used CGI to expand their number to 7,000 in post-production.