I keep live update turned off on most of my smart playlists because changing anything, such as ratings, for a currently playing song could cause the song to disappear from the playlist if it no longer meets the smart playlist's criteria. The song stops playing and the playlist grinds to a halt. So far, the easiest solution has been to have an Applescript run automatically in the middle of the night to quit iTunes and then launch it again, thus forcing all of my smart playlists to update. This works. It's also easy enough to right click on a smart playlist and select "Update Smart Playlist." But what I'd rather do is use an Applescript to refresh all of my smart playlists and assign it a hotkey (using BetterTouchTool).
Is it possible to use Applescript to make iTunes smart playlists update?