I was trying to get a Media Generator to play throughout the whole scene rather than fade in and out. I figured it out, apparently I had to tweak the color a bit. I was basically trying to use the "Starry Sky" to make a rain effect and I couldn't get it to actually play with the actual scene itself.

Drag your 'generated media'' to a video track above the track containing the video event. Put the cursor in the middle of it to see the result. Most media events have their proper transparancy setting you can play with. To create rain, play with the keyframes.

The problem in particular with the starry sky generator is that the background color is opaque and therefore covers up the image behind it. In the starry sky dialog box look for "Color B". Immediately under the word color is a vertical slider with a checkerboard. This is the Alpha control. Lower this slider and the background color becomes more transparent. Lower it all the way to the bottom and the background color disappears completely, leaving only the white stars visible on the image behind it.