You need a combination of things.
I would suggest that you start with a plain black background. You can find this under the Maps button on the middle toolbar. Drag a black background into your project from the Maps browser, and set its duration as long as you want.
Then pick a title and drag it on top of the black background. Set the length of the title to a length that you like.
Finally place a Fade Through Black transition between your black background and the first clip of your video.
The transition can be at most half the length of the shortest clip on either side, but it can be shorter than that if you like.
As AppleMan is probably still sleeping, I thought I'd jump in and suggest something that he would have also responded with.
The trick is to use a Cutaway. You can drag an image directly onto the video clip in the timeline. When the image is dropped, a pop-up menu will appear. Select Cutaway from the list. Now drag the Cutaway to the exact location on the video clip. Using the Inspector you can change the duration and opacity, apply video effects and fade in and out as desired. The Cutaway will not mute the audio in the underlying video clip.
Unfortunately, the black image (or any image) in the Map, Background & Animatic Browser can't be used as a Cutaway. So you will need to create or get the image from another source. Keynote can be used to create a black slide with the same aspect ratio as your video (for example, 1920 x 1080 or 1280 x 720). Or just take a screen grab (Command+Shift+4) of a black screen, then resize it, preferably with the same dimensions as your video.
Message was edited by: John Cogdell
OK Sorry, this would be simple in Final Cut Pro X which I have been using lately. I wrote this last night, but my browser had a glitch and I lost it. I am trying to recreate it.
In iMovie, there are a couple of ways to approach this. I don't have time right now to try them, but I will outline them and you can see if they will work for you.
1) You could select the beginning segment that you want to cover with the Title. Then right-click/Split Clip to separate this portion from the rest of the clip. Next select this newly split clip. Right-click and choose Detach Audio. Finally, drag the black background on this clip and choose Replace in the popup menu. It would be tricky to add a transition without messing up the timing of the audio.
2) You could select the beginning segment that you want to cover with the Title. Note exactly how many seconds and frames it is, and then Right-click/Delete Selection. Add the Black background and title and make them this length. Finally, select the same length from the exact same clip in the Event and drag it and drop it on the black background. In the popup menu, choose Audio Only. Once again, it would be tricky to add a transition without messing up the timing.
Your best shot at adding a transition without messing up the timing of the audio would be to try setting Transition Overlap to Half. Do this by double clicking on the transition and choosing Transition Overlap - Half in the popup.
I am not sure if this would work for you. See HELP here for more on Transition Overlap.
If you think you might be doing a lot of music videos, I highly recommend that you get Final Cut Pro X. It makes stuff like this easy, and it makes it possible to easily use multiple cameras.
I meant to add that when inserting the Title that you wish to run over the black clip, you need to drop it directly onto the video clip beneath the Cutaway (black clip). You can't drop it onto the Cutaway, but when played back the Title will appear over the black section and the underlying video will not be visible (unless of course you change the opacity of the black clip). The video clip's audio will still be heard, of course.
I've tested the Cutaway method I mentioned earlier. Using the Inspector it is possible to have the Cutaway fade, but unfortunately it fades both IN and OUT. The fade IN will reveal the underlying video unfortunately. But the fade OUT does not interfere with the audio. So, I'm thinking that no splitting is required and neither are transitions - this can all be achieved by simply fading out the Cutaway.
Again, the downside is the fade in of the black Cutaway at the beginning of the clip, which briefly reveals the video clip. Perhaps there is a workaround for that, but I'm beat and heading off for bed (it's 1 am in the morning here).
Oops! One more thing before I head off. Just looked at the Cutaway again. When played back it's now only fading OUT, which is what we want. That must have changed when I inserted the Title. So now my test starts with a black clip (the Cutaway), the Title appears and fades out (it's a Centered Title), then the black clip fades into the video clip (like a Cross Dissolve). All original audio is intact (and audible), including an inserted voiceover.