Your are still liable for copyright infrigement, wherever your music comes from.

   - so its not really any different than a blog posting a song their site.

And that's totally illegal since the owner usually doesnt give you the permission to do so. Did Grant Lee Buffalo label or Placebo label gave you the permission to broadcast their music ? Your host can shut down your website directly without warning following a DMCA takedown notice,if it is a US business.