Blurred Lines

I tried to get movement blur but it was a bit dark so I've managed to get the whole lot blurred! Never mind .
We are rehearsing a Christmas piece in our choir called A Christmas Mass by Ronald Corp.
It is a traditionally worded Latin mass set to music based on small fragments of well known carols. Just when you recognise a bit of ' I saw three ships' and start singing with great confidence, it morphs into something else having first changed key and time signature about four times.
Tricky!
So our wonderful accompanist is doing a few extra rehearsals over half term.
It helped. I think.