I think your target audience may be electronic music fans which might limit you in your service growing. I have seen a similar implementation of a StumbleHype however, it redirected to each blog. I like your implementation of loading the songs into a music player located on your site. You may already have this on your list of things to do, but, a categorization of music types might help, as well as it being more clear on how to pause the song that's currently playing. (Scratch part of that, your main page allow you to chose. You just linked to 'hot' tracks from HN.)
Hope this helps. I'm definitely a fan though.