How about letting each High School exercise their God Given freedom to perform as they see fit? Just as the US Constituition guarantees? Since Moslems don't have music, I don't see much competition.
And that was the way it was for many years. Heck, I'm old enough to remember prayer time in my public school classes. And around Christmas time the school choir put on a beautiful show, with many traditional songs of a religious nature.
Those were all good things. But back then, no muslim (or Buddhist, or whatever) would even think to sue over it. And if he did sue, no judge would grant the petition.
But as you and I know, times have changed. The islamist will sue, and the judge will grant the petition. Those are simply the unfortunate facts of today.