The key
At 7:40 there is the key: “Find the true essential feeling. I want your music to rouse the fragment of the infinite that sleeps in their stomachs.”
Please note that you are listenig to an “impossible” performance: Farinelli’s singing voice was provided by a soprano, Ewa Malas-Godlewska and a countertenor, Derek Lee Ragin, who were recorded separately then digitally merged to recreate the sound of a castrato.