To start a preview of video and audio, do any of the following: 1  Press any of Preview keyboard shortcuts (Spacebar, Numpad-0, or Shift+Numpad-0). 2  Click the (Play) button in the Preview panel. 3  Select Composition Preview Play. Click the (Play) button in the Preview panel. 2  When you click the Play button, settings assigned for the Shortcut, currently displayed in the Preview panel, is used. 3  Select Composition Preview Play. 4  When you select the Play option, settings assigned for the Shortcut, currently displayed in the Preview panel, is used.