They cannot pull a Michael Scott to declare bankruptcy or a financial emergency. There are several steps involved - including public hearings and board meetings. And who are these districts going to cut first - teachers who are delivering TEKS-based lessons to students, or support staff who work in buildings that aren't being used?
If this happens, on a wide scale, there will be bigger issues than a few band directors out of work - we're talking Great Depression 2.0.
So again, RELAX. And your entire argument has nothing to do with my point of "if they try to unilaterally include language in your contract making you an at-will employee, you should contact your teacher's association."