Music in Catalina doesn’t remember window size Each time I open the Music app in macOS Catalina (10.15.1), the window size is set to maximum. I then have to rescale it down to fit my use case. But after it’s been quit and reopened, it is again huge. I find it silly to use Music at its biggest size on a 27” screen!

Am I alone in this? If so, are there any steps I can take to fix this?
Had the same issue and on 43" monitor - not much fun.

Solved by deleting ~/Library/Preferences/com.apple.Music.plist

Make sure to create a backup of that file first and optionally create screenshots of your settings as those will be lost.