[pmullins]

I'm pretty sure that's exactly what they did. My understanding is that they based the macOS version on the iOS version. Explains quite a bit.

[kalleboo]

The macOS Catalina Music app is very much still based on iTunes. It still supports AppleScript, the preferences dialog is still a modal, it retains a bunch of subtle (not always desired) behavior in stuff like metadata edit autocomplete and multiple window support, etc, it even has the ancient legacy visualizer, it's all still iTunes.

The Podcasts/TV/Books apps that got split out OTOH I believe are all iOS ports