As a Band Director AND a single parent that recently (last year) had my oldest child in my own beginner band please remember that there are legitimately days that 20 min of practice truly are impossible especially when you factor in sports.

On days during Softball/Baseball season we were busy minimum 4 days of the week usually going straight from school to getting ready for practice/game and then getting home in time for a late dinner then going straight to shower/bedtime.

Please be courteous to your student's outside of school time especially when considering other classes have homework and each kid needs "be a kid" time....20 min a day doesnt sound like a lot but especially if they are trying to do it daily or batch it and get an hour in at the end of the week it can be rough.

Early in my career personally did away with practice charts because I found it leads to lying by the kids and the parents in order to save the grade...instead I did my best to pass out music that actively made the kids want to practice or tie it to an upcoming chair test that they wanted to do well on.

End of the day, the kids that were already going to practice will practice anyway and the ones that arent going to practice wont anyway