Understood. JMU seems to have everything you want, and an acceptance is certainly possible, just not assured. My thought was just that if JMU didn’t come through, WVU might be a more appealing alternative than some of your in-state back-up choices. It isn’t too far and the OOS cost isn’t too obscene (only about 5K/year more than VCU in-state, for example). The band doesn’t have 500+ members but it’s over 330 which isn’t bad!
But of course it depends on your particular situation whether considering OOS schools is practical or not. And if you do get into JMU, that seems to check all the boxes!
Another way to go about this would be to take the “JMU or bust” route; if you don’t get in on the first try, move there anyway and attend Blue Ridge Community College - BRCC students can join JMU’s band too! - and take the transfer pathway into JMU. It would be a bit more of a “DIY” experience, but you’d have band to connect you socially and the guaranteed transfer agreement seems worry-free: https://www.jmu.edu/transfer/vccs-transfer/ccinfo.shtml