Can't add a transition in iMovie
I have a background running the length of an audio track on my project. Above the background are clips that need to transition to each other. I am not able to drag and drop any of the transitions between my clips. It's only letting me insert transitions on the background part of the timeline, which I don't need because the same background is constant for the length of the project. Any ideas why I cannot add transitions between the clips that layer over my background?