You may know about the Option-click trick in the Finder. If you click on the disclosure triangle for a folder in list view, you open the folder; click on it while holding down the Option key, and all of its subfolders will open, too. This same trick works in iTunes – Option-click on a Playlist folder, and all of its subfolders open. But here’s another keyboard trick in iTunes. Click on a folder while holding down the Cmd key, and all of the folders on the same level as the one you click will open at once. Using Cmd-click works in the window where you select playlists for syncing, as well as in the sidebar of the main iTunes window.