To automatically loop the playback of a sequence in Premiere Pro the Loop Playback button needs to be active. This button can be accessed by pressing the plus sign (Button Editor) in the bottom right corner of the Program panel. Drag the Loop Playback button to the group of buttons at the bottom of the Program panel. Click the button to activate this feature. Now when the end is reached while previewing a sequence, Premiere Pro will loop the playback to the beginning. Pressing the Reset Layout button inside the Button Editor will return the buttons at the base of the Program panel to their defaults.