Why do you expect focus in rehearsal?
Some teachers expect focus as a sign of respect. Some teachers expect focus because they use it as a sign that students are taking the subject seriously. Some teachers expect focus because it’s the only way they can maintain order in class.
If I’m asking for focus in rehearsal, it’s for two reasons. First, because I think the chance to make music as an ensemble is a blessing that we can’t take for granted.
Second, and more important to drill home, is because if you practice focus now, you’ll be able to show focus in performance. An ensemble that practices without focus will have a hard time showing focus in performance, and that’s how mistakes happen.
Practice focus now, perform with focus later.