I just started singing in a choir as a tenor.
I have some training as a tenor (classical techniques) but I am not trained in choir singing.
The choir chose to sing a Kyrie by Philippe Mazé. It begins with a lot of D4s. That particular note is not difficult at all when I sing melodies. But it feels very different when I sing the note as a tenor in the choir.
D4 would be where my passaggio starts, I think. That seems to be the reason for the note being a bit difficult. It's like tenors stay in chest voice but ads more head resonance to the note.
How do tenors deal with it?
They don't say anything about vocal technique at choir practice. They just tell you to sing. That might be because you are supposed to learn that at other times. You should already know the repertoire before going to practice?
The sheet music for the first part of the piece: https://i.ibb.co/bzRXMbT/16941621771447573998051645670809.jpg