So, I offered to take the men to rehearse their parts. She took a chance, not knowing me either, and let me take the men off to another space to rehearse. She told us when to return. We did a few warm-ups and proceeded to go over the Tenor and Bass parts. Then, in walked the guy who had been invited to work with the men. He was a full half hour late! We were actually just getting ready to go back into the main rehearsal.
Without even considering the time, this man proceeded to start from "his" beginning. He took these men through a grand College lecture about preparing to sing and had them do many vocal warm-ups. (He asked me to stay to play the piano, so I witnessed it all.) He never actually got to the practicing of parts before the Conductor sent a runner to beg the men to return to the main rehearsal. This man was rather put out. (He had not even considered that the rehearsal I had already done with the men was valid.)
I had already been working with the men on practicing the INCEPTION OF THE SOUND or LIFTING THE SOFT PALATE while taking the initial breath. We practiced setting the abdominal wall muscles to support the tone, correcting posture, and breathing in the shape of the vowel all from that one concept. It seemed to be working well, too. Anyway, at least we had gotten some woodshedding of the parts done before that man came!
Here are some Warm-ups I have collected over the years.
Fun and Easy Warm-up Songs for Choir