Reply to How to DJ's get unreleased tracks and such

So many tracks I love are unreleased/not on beatport or iTunes yet I hear DJs playing them out all the time. Do they just get them from the artists?

When I am practicing and such I dont mind using a song I ripped from youtube but there is no way I would actually want to use them due to sound quality and the like. So other than ripping songs from youtube or soundcloud how do you obtain these tracks?