The other day in orchestra, we were reading a student composition and the tubist had two isolated whole notes. These notes severed as the underlying harmonics for a short choral in the winds and brass. The first time through, he put a huge breath right in the middle. The second time he supported through the choral, making the whole orchestra sound better. I doubt the other wind players noticed much of a difference, other than their parts sounded a lot easier with a more clear idea.
Yesterday, I coached a high school trombone section through a choral. All of them knew their parts but had little idea how their parts functioned within the section. (B in fig. 1) Slowly, as the listened to where harmonies changed or where other people had moving notes a more clear section sound emerged. (C in fig. 1)
How does this make it easier for others to play around you? The 1st trombone had an octave leap over a bar line, while the rest of the section repeated their harmony. This should have been a huge energy creating moment, but the principal had to work so hard to play his octaves energy was lost. Rather than ask him to push through the bar line, I had the other three musicians push through their parts. In supporting their own lines, they were supporting the first trombone part, making his job much easier. (D in fig. 1)
One of my students mentioned this process was like twine being worked into rope. Knowing your part is only the first step, knowing where everyone else's parts are going will help a section or entire ensemble know where they are going.