Sure you can. If you read the article, you'll note ...Whether homeschool students can be in marching band is at the discretion of each school, said Jim Tenopir, director of the NSAA.
So, it is permitted, and it is at each school's discretion.
So you can pick and choose if you are in the right school district.
So you can pick and choose if you are in the right school district.
Not trying to nit-pick here...but your statement contradicts itself. If it is at the school's discretion, then no, the parent/student does not get to pick and choose. The school gets to make the decision.