After adding operatic vocals to Gojira's rendition of "Ah! Ça Ira," a song popular during the French Revolution, she went on to sing a portion of Georges Bizet's Carmen.
From NME:
The heavy metallers performed ‘Ah, Ça Ira!’ (which translates to ‘It’ll be fine’), a song that was popular during the French revolution, during a segment titled ‘Liberté’ (in reference to France’s famed motto ‘Liberté, égalité, fraternité’) that celebrated one of the most famous events in French history, as well as the nation’s emphasis on freedom.
Gojira appeared on the side of a castle surrounded by fire and bursts of red streamers to represent blood, with Viotti later appearing on a moving prop boat. Their performance followed a portion dedicated to Les Miserables and came just after a beheaded Marie Antoinette was shown singing.
Traditional lyrics translated at wikipedia (linked above) Gojira's lyrics translated via redditors:
Oh. It'll be okay, be okay, be okay,
Hang the aristocrats from on high!
Oh. It'll be okay, be okay, be okay,
The aristocrats, we'll hang 'em all.
Despotism will breathe its last,
Liberty will take the day,
Oh. It'll be okay, be okay, be okay,
We don't have any more nobles or priests,
Oh. It'll be okay, be okay, be okay,
Equality will reign everywhere,
The Austrian slave will follow him,
To the Devil will they fly.
Oh. It'll be okay, be okay, be okay,
To the Devil will they fly.
I wish I could remember the source, but it was about the Catholic Church in central/south America with the gist of, 'When I was young, I hated The Church for building grand structures amid an impoverished population. I thought they could spend the money better on food, education, or so many other things -- but as I got older, I realized that having a glorious space to share with the community was worthwhile in its own right.'
I'm not saying that the Olympics aren't vulgar, but at least a lot of it is carried on network TV so it is more public than, say, the latest Marvel movie that not only costs a fortune, but also requires everyone fork over the cash if they want to see it.