This weekend I tried to add beat markers to a video for a colleague. But the beat marker menu option was grayed out, and I spent some time searching for the “Clip Trimmer” everybody was talking about. I was in a bit of a hurry and all the right-clicks, top menu, gear-icon popup menus, and shortcuts made me overlook the thing I was looking for. Maybe you overlooked it too. It’s not much of a tutorial, but if you need to add beat markers to your background music, here’s how to get to the correct “Clip Trimmer” in iMovie ’11.