Craig Jessop was our guest conductor. He had formerly led the choir and many of us were thrilled to get to sing under his baton once more. He was so nice to compliment us and say, "You've still got it!" Then he jokingly said, "Okay, the concert is tomorrow. Let's tape and time it." (Crowd erupts in giggles!)
The way choral conductors often rehearse is to break up the songs into sections. He (or she) may just spot rehearse certain parts, then go on to the next piece and do the same. Most are under a time crunch to get things learned before a concert. They are just trying to get through all of the material and make sure all the spots that need help are addressed. It is so easy to just run out of time.
At the latest concert I performed in, I really don't think we ever sang some of the songs from start to finish. We only sang bits and pieces in a disjointed order. I realized that at the performance was the first time I had sung some of our repertoire from beginning to end without stopping to work on something. That's when I really appreciated the Tabernacle Choir's mandatory "Tape and Time."