Choral phonetics uses our hidden ability to perceive resonances in the vocal tract as pitches (→ hearing test). And it trains a special fine motoricity of the tongue to control these resonances and to adapt the timbre to chords. This know-how enables singers to tune resonances just as precisely as their vocal tones. This turns timbre into a musical instrument. Choir sounds, as they can be heard in the video, become controllable.
What otherwise requires many years of experience and voice training for choristers can be achieved much faster with the knowledge of choral phonetics. Choir singers and conductors usually learn the necessary vocal techniques in just a few days and can develop them into a retrievable skill set within half a year. This refines not only intonation and homogeneity in the ensemble, but also the carrying capacity and lightness of the voice.
Besides, Barnaby Martin has a great talent to explain complex musical phenomena in a simple and entertaining way. Be sure to subscribe to his YouTube channel “Listening In”, there are a lot of first-class videos about the effects of musical sounds.Among other things I recommend his video about the completely crazy intonation movements that Jacob Collier uses in his choir pieces. Guys, choral phonetics is slowly becoming mainstream :)!