Well, for one, you can t make a business out of this unless you get the permission of the people who own the rights to the music. It s cool to make these kinds of videos for fun, but as soon as you start to try to make money off of this idea, the owners to the copyright will either have an attorney file a cease and desist notice against you to shut you down, or they will demand a fee. And if they demand a fee, you can bet that it s going to be extremely expensive. To answer your question, yes, anyone, including a multimedia company, can use your idea. If you watch TV, you d see that after a show becomes popular, lot s of copycat shows come out that try to emulate the original. That s the way business goes - find something popular, and change it just enough to get around the accusations of stealing, and run with it.
Yup. Ask Google or Microsoft.
