when a person composes a video and puts it onto youtube, he is fully aware that he is going public & taking a chance of people downloading it. Thus by realizing this he is accepting the risk of it happening & telling everyone that he is willing to go onto youtube-for the advertisement of his video-even if people will download it & use it without buying his CD.
BOTTOM LINE: it is fully permitted but you may double check with your local orthodox rabbi to be on the safe side
to the singer or Entertainer etc…: if you are afraid you will lose money by less people buying your CD’s etc.. then don’t download yourself onto youtube. cause millions of people go there everyday. you have the free will to decide the pros & cons if its worth it to put yourself onto youtube or not
Hatzlacha to everyone