In Dune part 2, shortly before the arena fight starts, everyone in the audience starts shouting following a leading voice, very interestingly, there is no subtitle during this entire sequence.
I am wondering what they are speaking of?
It happens from 3:42 to 4:17 in this video.
There are no real song or words. In this interesting aticle on Variety, they just describe what they used to make the crowd "cheer and sing". There are no explanation about the technical part or how they can achieve that, and I think they won't disclose how the magic is done because, for the recording and arrangements, it's some kind of industrial secret.
When it came to the sound, Walker and Villeneuve knew two things: that it would not sound like a modern-day sporting event, and there would be no applause. “The noise is from chanting and stamping which is a great sound. Dave Whitehead was working for us in New Zealand and started recording a male crowd with specialized vocal skills within the punk and death metal music scene, stamping and shouting.” The scene was divided into 30 sections with a view to looking at where the crowd would be. “When is the Harkonnen crowd at 10? We wanted 10 to be when Feyd rips his shield off, and again at the end when he’s changed as a Harkonnen and is no longer just a playboy prince.”
As mentioned in a comment, there's nothing more disclosed at this moment.
The film's editor describes it as a 'Haka'
Denis had also developed a number of behaviors for the Harkonnens - the way that they clasped their hands together and they don’t clap.
So, a massive Sport events with tens of thousands of people not clapping, you have to do something. So we were engaging from day one of the shoot with the Sound team to say, let’s have a look at Haka, the Maori chant. Dave Whitehead offered that up and did a kind of fantastic Harkonnen haka. Then let’s have a look at stamping in this massive arena – and building it into the fabric of the cut.
