This week’s vocalize is the entire melisma including last week’s vocalize at the very end of it.
This exercise is all about breath control. The tempo of the midi is somewhat on the slow side, which may be a bit much to start with. My suggestion is to start faster singing either on Mi to encourage a resonant tone or on Solfegge syllables to encourage proper intonation. As the choir gets comfortable with the phrase, slow it down and have them concentrate on their breathing. Breathing should be from the diaphragm and shouldn’t be done in a way that causes muscle tension.