hello, I have seen music mixes for free download on the net that actually contain copyrighted tracks, is this legal? Can I make a mix from copyrighted tracks and then make it available for free download?
many thanks, J.M.

My understanding is this would be illegal without the copyright owners' permission.

You need to contact the copyrightholders of each track to license them. Another way is to broadcast the mix on a radio station which pays volume licensing fees with permission to put up shows for download, and put up the radio show for download.

thanks