You don't have to pay royalties if you upload on YouTube.
However, Google (which is in the process of taking over Youtube), has indicated it will remove video's containing copyrighted music. But that's all they will do. Remove the video. They may at worst ban you if you are a persistant offender.
Google still hasn't taken over the site. So in the meantime I would just stick it up there.
There are millions of clips containing copyrighted music.
It will be a long time before they can remove them.