The problem is because in reality there is no such thing as non copyright or uncopyrighted music. You can give the rights away if you want, but copyright always exists somewhere. Searching for license free or other terms often brings back more results. Music producers can allow you to use their music free of charge if they wish, but only very rarely will they give copyright away. The trouble is that if you run a site and make the tracks available, you need proper permission from whoever does really hold the rights - and this is what causes problems. I could give you a track but how would you know it was ok to use? Would you take my word it's mine to give away. Very often crafty producers allow their work to be distributed and just wait for it to be played on radio 1, when they announce their ownership and wait for the royalties to arrive.
One of the songs on your youtube site is Phil Collins Groovy kind of love - hardly dubstep and NOT copyright free. Another of your dubstep links has a tiny note on the linked page that saysCop outs like this do not mean they have no copyright issues - download this - but only when you have gained the direct permission of the artist is not really going to work, is it?All Uploads Are Free To Download With The Labels Or Artists Direct Permission.
I see no point in a site linking to other people's pages when all you're doing is just picking your favourite tracks that may or may not be legal.
If you are going to do it properly, then you need to research it a bit better. Copyright free is an oxymoron - it doesn't exist. No fee to use could be accurate, but copyright resides with somebody or a business.