How to duplicate a generator below connected media? I have my main story line and then I've added still frames of a presentation throughout. The images are displayed ontop of my video and the images don't cover the entire screen, so I can add a solid black generator under each image and it works great.

The problem is that I have 60+ images and I want to avoid to cut the video or add the generator manually for every image. Is there a way to paste a generator below every image? As you can see in the image, the duration of each image changes, so the brown boxes (solid black background) should match the duration of each connected image on top. Is there a way to automate this?
I got the answer from someone at fcp.co. He made a video: vimeo.com/93836074

Basically: 


add the generator to the timeline (don't worry about setting the duration since you're going to delete it)
turn it into a compound clip, delete it from the timeline (since it gets added to the event manager)
copy the image frames and paste them with the playhead at the first image
create a compound clip with all images (the ones in the bottom, so there's an actual image on top)
right click to open it in timeline
select the black compound clip in the event viewer and press x then d (black gets added)
press down arrow and repeat x then d


Pretty slick