[delayed]

This has never happened to me. I exclusively listen to music on my phone, and work every day on my Mac. I have never had the Music app open itself up, not once. Nor I have I experienced anything that is even related to music, such as asking me to subscribe to a service.

It doesn't pop up on its own, but it is the default response to a lot of actions.

Accidentally press the play button? Apple Music. Charge your iphone through your computer? Apple Music.

I find it pretty annoying, but it is also easy to eliminate the default behavior

I've never had Apple Music open when I plugged in my iPhone

I leave Music running all the time. I have all the store and subscription features turned off. I just have the program loaded with all of my MP3s, something I've been doing since it was called SoundJam MP [1]. I have all my playlists in there and it works fine with the play/pause/prev/next buttons on the keyboard. I think they bug me about subscribing to Apple Music once every major OS update. I promptly say no and turn off any of the extra features they added.

[1] https://en.wikipedia.org/wiki/SoundJam_MP

Got a touchbar?

I discovered the fingers on my right hand barely brush the bottomed edge of it when I make certain multi-key keystrokes. Right where the play “button” was by default. Took me forever to figure out why Music was opening “randomly”.

I ended up setting the touchbar to static, not per-program customizable, and replacing most of it with a “spacer” element. Fixed the problem.

Luckily they’ve realized they were a bad idea and my newer ones don’t have a touchbar.

Play/Pause press on a headphone will also do it. And there's just no way to disable that.