http://www.scratch.mit.edu/ext/youtube/ … ature=plcp
The link above is a video by KatieCadet1.
You will need a youtube to gif converter and a youtube to mp3 converter to do that!
And you will need to import the gif and mp3 files you converted in the first place into the Scratch Program.
You might need to get the timing right for the audio and video to sync correctly in both the Java and Flash Players.
Once done, you can submit it into your Scratch Profile.
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I've written a wiki article about importing videos a while ago.
http://wiki.scratch.mit.edu/wiki/Importing_Movies
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