Play/pause always starts the Music app, regardless of your preferred music player. It's annoying for those of us who don't use the built-in Music app at all.
Your command doesn't work. The music app actually lives at `/System/Applications/Music.app`. And since Monterey, I think, even sudo won't let you modify data in that folder because of macOS's built-in protections that cannot be disabled:
chmod: Unable to change file mode on /System/Applications/Music.app: Read-only file system