Firstly, .app is a bundle, so sudo chmod -x /Applications/Music.app/Contents/MacOS/Music Secondly, on modern macOS you'll have to disable system integrity pro

Firstly, .app is a bundle, so sudo chmod -x /Applications/Music.app/Contents/MacOS/Music Secondly, on modern macOS you'll have to disable system integrity protection for this to have a chance of succeeding.