Ask HN: : How do I get a streaming deal and legality of MP3 blogs?

I created CurrentHipHop.com, which allows streams/downloads of hip-hop music. 90% is free music (covers, freestyles, free mixtapes), but a small portion is still copyrighted (leaks, promotions).

I built it as a better version of HotNewHipHop.com, which gets more than 300k unique visitors a month and is run by a prominent DJ in the hiphop community (working with guys from Lil Wayne's group + others). He's been at it for two years and has steered clear of legal issues. How?

I do want to go the completely legal route and somehow score a licensing deal for the 10% of music on my website. I am completely lost on how to go about it.