 By pure coincidence, I discovered that you can use Apple Music Classical with CarPlay. When you engage CarPlay, simply hit play on the Apple Music Classical app on your phone, and it will play in your car. Then launch the now playing app in CarPlay, and it will display what is playing in the Classical app. You can switch tracks, pause, etc. But if you want to play a different album, you have to switch to it on your phone. Weird. You can use the Zoom app, but we'll add the Classical app to CarPlay soon, but this is an interim solution. I hope it helps two or three other Classical music lovers out there. There's a general tip here too. If you're playing audio from any app that doesn't yet support CarPlay, you get it started on your phone, and then use the now playing app to give you control over what's playing as much as it can.