Sierra has a new Finder alert sound when you attempt an invalid operation. (Either it is new or I had never noticed it in many years of Mac OS X/OS X/macOS use.) For example, try Command-Delete on an empty space on the Desktop. Finder sounds the alert selected in System Preferences > Sounds. This alert does not honor the preference for “Play user interface sound effects.” (The Finder alert still plays when that setting is deselected.) Is there any way to disable that alert sound? Finder does not appear to have a setting for it.