I want to start an aio website that will consist of mp3, music videos and 18+ videos which will be an easy one click download. Do we need to get a license or is it enough if we mention the source of the content?
Yes. Well... it's more complicated. Some artists have restrictions and 'royalty free' does not necessarily 100% free. I have a list somewhere that explains usage rights. Most sites have this in their terms with restrictions. Please double-check where you are getting the source files from.
If the content is someone else's you will need a license to share something you don't own UNLESS you get Creative Commons material. If you're creating the content you do not need a license to publish it however you will want documentation for others who want to publish your original content.
