Outdoor Masses can be a real struggle because the chant can die outdoors without serious audio adjustments. In this case, this Papal Mass dealt with it in a way that is rather common: organ accompaniment with mixed voices. The verses they chose to sing in choral style with a rather nice arrangement. The results are completely different from what we experienced in our parish yesterday but it is still beautiful and interesting.
At the same time, listen to how spectacular this Palestrina motet comes off in the same venue. This is so wonderful.