Aggregators

Aggregators such as The Hype Machine and Elbo.ws track MP3 blog posts and display the most recently updated posts on its front page. The services are meant to provide a snapshot of what's going on in music blogging and make it easier to search through recently posted MP3s. The Hype Machine features a list of the most popular tracks of the last 3 days as well as the most blogged bands and most popular searches. Elbo.ws has a similar feature listing which Bands, Tracks, and Videos are currently "hot." Music Blog Aggregators have caused a boom in MP3 blog readership and accessibility. Aggregators use RSS technology to collect data from MP3 blogs and link to the individual blog posts instead of directly to the MP3s.
Reference : http://en.wikipedia.org/wiki/MP3_blog